16 avo TALLER DE BIOLOGÍA FORESTAL DE AMÉRICA DEL
NORTE
“Impacto del cambio ambiental global sobre los bosques e impacto de los bosques
sobre el cambio ambiental global”
MÉRIDA, YUCATÁN, MÉXICO
Julio del 2000
PRESENTACIÓN
La Secretaría de Agricultura, Ganadería y Desarrollo Rural a través del Instituto Nacional
de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), la Delegación de la
SAGAR en el Estado de Yucatán y la Comisión Forestal de América del Norte (COFAN),
en coordinación con el Gobierno del Estado de Yucatán a través de las Secretarías de
Desarrollo Rural y la de Ecología, la Fundación Produce Yucatán A. C., la Universidad
Autónoma de Yucatán, el Centro de Investigación Científica de Yucatán A. C., la
Universidad Marista, el Consejo Nacional de Ciencia y Tecnología, el Instituto
Tecnológico Agropecuario No 2, Conkal, la Secretaría del Medio Ambiente, Recursos
Naturales y Pesca, el Instituto Nacional de Capacitación del Sector Agropecuario A. C., la
Sociedad de Forestales Americanos (SAF) y la Asociación de Genetistas Forestales del
Oeste de E. U. (WFGA), convocan a la comunidad científica forestal, a los profesionales
forestales y afines, así como a las personas interesadas del sector público y privado de
Canadá, Estados Unidos y México, al "16 avo Taller De Biología Forestal de América del
Norte", “Impacto del cambio ambiental global sobre los bosques e impacto de los
bosques sobre el cambio ambiental global”, que se llevará a cabo en la ciudad de Mérida,
Yucatán, México, del 16 al 21 de julio del 2000.
ANTECEDENTES
Los Grupos de Trabajo en Fisiología y Genética Forestal de la Sociedad de Forestales
Americanos (SAF) han organizado de manera periódica desde hace 30 años el Taller de
Biología Forestal de América del Norte, como un foro para presentar y discutir los avances
de la investigación básica y aplicada en las diferentes disciplinas de la Biología Forestal, en
el contexto del manejo sustentable de recursos forestales y de la problemática en general
que enfrentan los bosques en Norteamérica. En esta ocasión, con el apoyo de los Grupos de
Estudio en Recursos Genéticos Forestales, Silvicultura y Cambios Atmosféricos de la
Comisión Forestal para América del Norte (COFAN), la Asociación de Genetistas
Forestales del Oeste de E. U. (WFGA) y las Instituciones Mexicanas anfitrionas se organiza
por primera vez este Taller en México. En las reuniones anteriores se ha destacado la
necesidad de reforzar los vínculos y esfuerzos en el ámbito regional con el fin de mejorar la
comunicación e intercambio de experiencias, especialmente en aquellas áreas que tienen
repercusiones en el ámbito global, como lo son actualmente las interrelaciones entre los
bosques y el cambio ambiental.
Problema por abordar
El desarrollo forestal en la región de América del Norte, a pesar de los avances
tecnológicos, no alcanza todavía los niveles y resultados esperados por los sectores
oficiales, privados y gremios profesionales; sin embargo, existen grandes expectativas
sobre la contribución y el papel que esta actividad debe jugar en el desarrollo sostenible de
los países de la región, especialmente ante el reto que plantea el ingreso a un nuevo
milenio. Aunado a esto, los acuerdos adoptados durante la Conferencia Mundial sobre el
Medio Ambiente de 1992, plantean una serie de desafíos, metas y resultados esperados que
deben ser analizados y evaluados con el fin de establecer mecanismos y estrategias que
contribuyan a potenciar dichos acuerdos. Los profesionales forestales han sido testigos y
actores de una significativa evolución en los enfoques y desarrollo de políticas y estrategias
sobre el uso de los recursos forestales en los últimos años. Un problema común que se
enfrenta es la gradual disminución de las superficies de bosques y selvas, con el inexorable
deterioro de los recursos genéticos forestales, la disminución de la biodiversidad,
particularmente en las selvas, y sus repercusiones en el ambiente en general. Con la
participación de investigadores de diferentes países se abordarán los avances recientes en
las diferentes disciplinas de la Biología Forestal (Fisiología, Genética, Ecología,
Silvicultura, etc.), especialmente en lo que se refiere al “Impacto del cambio ambiental
global sobre los bosques e impacto de los bosques sobre el cambio ambiental global”. La
generación y difusión de nueva información son indispensables para que las empresas
forestales, comunidades rurales y demás Instituciones que participan directamente en el
manejo de los recursos forestales logren sus propias metas de desarrollo.
OBJETIVOS
El objetivo fundamental es intercambiar experiencias y discutir el estado actual del
conocimiento en el área de la Biología Forestal como base científica para asegurar el
manejo y conservación de los bosques y selvas en el ámbito regional, ante los retos que
plantea el cambio ambiental global. Asimismo, se pretende contribuir al desarrollo de
estrategias de desarrollo del sector forestal que propicien una mayor calidad de vida de la
sociedad en general. Otros objetivos son: Discusión de las interrelaciones existentes entre
los bosques y selvas y el cambio ambiental global. Análisis del papel de la Biología
Forestal en la generación de conocimiento para un mayor entendimiento de esas
interrelaciones. Lograr un mayor acercamiento entre los países de la región para desarrollar
políticas y estrategias comunes. Análisis del potencial de los recursos forestales, a fin de
lograr una contribución más significativa en los programas de desarrollo socioeconómico
en el ámbito de los países y la región en su conjunto.
TEMÁTICA
La temática que enmarca este importante taller es:
Cambios en las condiciones atmosféricas (Changing atmospheric conditions).
Captura de carbono (Carbon sequestering).
Semilla recalcitrante y conservación de germoplasma (Recalcitrant seed & germplasm
conservation).
Respuesta biológica al cambio (Biological response to change).
Respuesta de la vegetación y cambio climático (Vegetation response & climate change).
Genética y mejoramiento de árboles forestales (Genetics and forest tree improvement).
Fisiología de árboles forestales (Forest tree physiology).
Cruzamientos para tolerancia al estrés (Breeding for stress tolerance).
Silvicultura tropical (Tropical silviculture).
Adaptación y cambio climático (Adaptation & climate change).
RESÚMENES
INVITED PAPERS
CONFERENCIAS MAGISTRALES
GLOBAL CLIMATE CHANGE AND ITS IMPACTS ON THE TERRESTRIAL
ECOSYSTEM. Sagar Krupa
(krupa001@maroon.tc.umn.edu)
Department of Plant Pathology, University of Minnesota, St. Paul, MN 55108, USA
Abstract: Global climate change is a complex, integrated system of atmospheric processes
and their products. Among the many variables involved, of concern in the context of
terrestrial ecosystems are increases in the concentrations of carbon dioxide (CO2) and
ozone (O3) and levels of ultraviolet (UV)-B (280-315 nm) radiation and changes in the air
temperature (T0C) (climate warming) and precipitation patterns. There is a significant
temporal and spatial variability in the occurrences of these variables, particularly with
elevation. For example, high elevation forests are subjected to distinctly different patterns
of CO2 and O3 exposures compared to the low elevation ecosystems. Similarly, although
there are several models that predict future increases in the average global air temperature,
historical records for the last 100 years show no measurable increases in the average daily
T over North America, but a clear increase in the nighttime T during the last several
decades. Independent of these observations, data from multi-year measurements of the
parameters relevant to forest ecosystem responses are relatively sparse. Among all climate
change related parameters, at the forest ecosystem level, emphasis during the last three
decades has been on the effects of O3 and other photochemical oxidants. With the
development of ambient exposure systems, there is an increasing effort to study the effects
of elevated CO2 concentrations. Forests are both a sink and a source for CO2. Only recently
have scientists begun to study the importance of this flux, relative to the storage of C in
forest ecosystems. Results from a four-year study show significant inter-annual variability
attributed to temperature and soil moisture availability. Overall, there are a number of
uncertainties associated with our current knowledge of climate change effects on forest
ecosystems. Although many of the simulation models have produced differing outputs, one
can nevertheless, draw some general conclusions.
TROPICAL N-FIXING TREES, VIRUS RESISTANCE, AND THE COLLAPSE OF
MAIZE-BASED CIVILIZATIONS. James L. Brewbaker
(brewbake@hawaii.edu)
PRESENTATION PROVIDED
Dept. Tropical Plant and Soil Sciences, University of Hawaii, 3190 Maile Way, Honolulu,
HI 96822
Abstract: The Classic Maya civilization of 300 to 900 AD thrived on the calcareous
Yucatan peninsula. Two factors undergirded its growth to >2,000,000 people–maize and Nfixing trees. This incredible civilization collapsed mysteriously in the 9th century.
Abandoned were 1300 ceremonial centers and, importantly, rich agricultural lands that had
been carved out of tropical rain forests without metal tools, wheels, or beasts of burden! No
reoccupation occurred of these farms and temples. Survivors presumably migrated south to
highlands and northward to areas (e.g., Chichén Itzá) with a long dry season. It is evident
that legume tree regrowth in fallow periods undergirded the remarkable intensity of Maya
maize culture. A leafhopper-borne virus of maize is believed to account for the collapse
(Brewbaker, 1979, Econ. Bot. 33:101-118). The hopper and virus are restricted to maize,
thus to areas (e.g., Hawaii) where maize is grown year-round. Maize diseases are
implicated in similar collapses in the late 1st and early 2nd millennia of maize-based
civilizations of Zapotec, Teotihuacan and Anasazi peoples. Tropical forests are currently
lost (often to corn fields) at a devastating rate exceeding 1% per year. Sustainable
agroforestry systems with multipurpose trees of immediate value to local peoples offers one
of the few long-term solutions to this loss. N-fixation is integral to the success of such
systems in tropical soils, and NFTrees have evidently evolved with high virus tolerance.
Breeding of tropical trees wisely focusses on the exploitation of interspecific heterosis of
multipurpose trees that can be used (as green manure, forage, food, shade, and yes wood)
by the four billion people living in the tropics. But who is going to pay for it?
EL USO DE ESPECIES ARBÓREAS MEXICANAS PARA PROPÓSITOS
PALEOCLIMÁTICOS. José Villanueva Díaz1, Dave W. Stahle2, Matthew D.
Therrell2, Malcom K. Cleaveland2 y Jorge Sánchez Sesma3.
1
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias (INIFAP), Santos
Degollado 1015Altos, Col. Cuauhtémoc, San Luis Potosí, S.L.P. 78270, México. Teléfono
y Fax: (48) 13 91 51. Funprod@prodigy.net.mx
2 Tree-Ring Laboratory, Ozark Hall 118, University of Arkansas, Fayetteville,
R7270, USA. Telephone: 501-575-3703. Dstahle@comp.uark.edu
3 Instituto Mexicano de Tecnología del Agua. Paseo Cuauhnahuac 8532. Col. Progreso,
Jiutepec, Morelos. 62556. Jsanchez@tlaloc.imta.mx
Las cronologías mexicanas procedentes de anillos de algunas especies arbóreas son
particularmente sensibles a cambios de precipitación y aquellas generadas en el norte de
México (Durango, Coahuila, Chihuahua y Sonora), registran de manera particular la
influencia a largo plazo. Del fenómeno del Niño, Oscilación del Sur (ENSO) y del Monson
Mexicano (MM). Trabajos conjuntos con el personal investigador del Laboratorio de
Dendrocronología de la Universidad de Arkansas (UA) y con investigadores del Instituto
Mexicano de Tecnología del Agua (IMTA), han derivado en la obtención de nuevas
colectas de abeto o Douglas-fir (Pseudotsuga manziesii) en sitios de la Sierra Madre
Oriental de los estados de Coahuila, Querétaro, Veracruz, Hidalgo y Tlaxcala y en algunas
localidades de la Sierra Madre del Sur en Oaxaca. Estos rodales aislados de Douglas-fir se
encuentran restringidos a exposiciones norte generalmente en sitios con pendientes
escarpadas, suelos someros y microclimas húmedos y fríos a elevaciones entre 2350 a 3400
m. Los árboles de esta especie muestran anillos de crecimiento bien definidos con edades
que fluctúan entre 200ª 300 años de edad, que pueden ser visiblemente divididos en bandas
de madera temprana y tardía, cada una influenciada por condiciones climáticas distintas
durante su formación. Una reconstrucción de precipitación para el período invernal y de
verano de 600 años de longitud con esta especie en el estado de Durango, muestra la
presencia de períodos secos en los siglos XV, XVIII y XX. Otra especie que ha sido motivo
de extensa colecta es el sabino o ahuehuete (Taxodium mucronatum) especie que se
encuentra ampliamente distribuida en territorio mexicano y que se considera el árbol
nacional de México. Muestras maderables de esta especie se colectaron en fechas recientes
en el “Parque de Chapultepec” de la Cd. De México, “El Vado”, Oaxaca y “Jalpan”,
Querétaro. Estas muestras no han sido analizadas completamente y aún no han derivado en
índices cronológicos, aunque existe el potencial para ello, debido a la presencia de anillos
de crecimiento anual bien definidos. Las muestras del “Parque de Chapultepec”, indican
visualmente períodos de crecimiento restringido a mediados del siglo XIX y una liberación
en crecimiento a inicios del siglo XX. Lo anterior puede estar relacionado a condiciones de
menor o mayor precipitación. Dos cronología de ahuehuetes de 400 años de longitud se han
desarrollado de colectas obtenidas en Río Sabinas, Tamaulipas y Río Verde, San Luis
Potosí. Análisis preliminares, indican una buena correlación entre la cronología del Río
Sabinas y la lluvia total para el período mayo-junio, si lo anterior se corrobora con
posteriores análisis estadísticos, entonces será posible utilizar esta cronología como
“proxy” para una reconstrucción de factores climáticos. La reconstrucción del período
mayo-junio en esta región es muy importante para las actividades agropecuarias y forestales
y un análisis histórico de esta variable resulta primordial para un mejor entendimiento de la
influencia histórica de esta variable climática en las actividades indicadas. México es un
país rico en biodiversidad y es muy importante tomar ventaja de esta condición y explorar
el potencial dendrocronológico de nuevas especies presentes en climas templados,
semiáridos y tropicales. Actualmente estudiamos tasas de crecimiento y colectamos
muestras maderables de mezquite (Prosopis spp), encinos (Quercus mexicana, Q. Rugosa,
etc.) especies localizadas en zonas semiáridas y templadas y que tienen alta demanda para
leña, carbón muebles, etc. En zonas semitropicales hemos observado la presencia de capas
de crecimiento anula bien definidas para especies como cedro (Cedrela odorata) y
liquidambar (Liquidambar styraciflua) especies tropicales maderables muy importantes.
Probablemente con algunas de estas especies no sea posible generar cronologías para fines
paleoclimáticos, sin embargo esta información puede ser de fundamental valía para un
mejor aprovechamiento y conservación de las mismas. Para realizar esta tarea contamos
con el apoyo económico de instituciones internacionales como lo es el de la Universidad de
Western Ontario, Canadá, a través de un proyecto financiado por el Instituto InterAmericano y por personal investigador del Laboratorio de Dendrocronología de la
Universidad de Arkansas, de los cuales hemos recibido un apoyo incondicional mediante
un proyecto colaborativo de investigación financiado por NFS. La problemática del agua es
un tema cada vez más relevante en muchas regiones de nuestro país, debemos hacer mayor
uso de esta herramienta para conocer el pasado y contar con mejores fundamentes técnicos
para entender el futuro.
POTENTIAL CONTRIBUTIONS OF MANAGED FORESTS TO CARBON
SEQUSTRATION: A CASE STUDY EXAMINATION OF SOPUTHERN PINE
FORESTRY. K.H. Johnsen
(kjohnsen@fs.fed.us)
Southern Research Station, USDA Forest Service, 3041 Cornwallis Road, Research
Triangle Park, NC 27709, USA
Abstract: The South represents about 24% of the land area of the United States; outside of
Texas and Oklahoma, about 58% of this land is forested and about 20% of the forestland is
owned by forest industry. From 1962 to 1992 the total land area of commercial pine forest
rose 27% to 11,291 million ha. The extent of managed forests has increased because
southern pine forests are extremely productive. The warm climate of the south extends the
growing season and reduces rotation length; pines reach sawlog size in 25 to 35 years on
many southern sites. In managed forests, the amount of C further sequestered (relative to
present day) will be determined by three factors: 1) the increased amount of C in standing
biomass (due to land use changes and increased productivity); 2) the amount of recalcitrant
C remaining belowground at the end of the rotation; and 3) the amount of C sequestered in
products created from the harvested wood, including their final disposition. Therefore,
managed southern pine forests sequester C both in situ (biomass and soil) and ex situ
(products). In my talk. I will assess the magnitude and primary controls of the major C
pools, suggest management options for increasing C sequestration and indicate important
research needed so that Southern pine forest C sequestration can be better quantified,
predicted and managed.
GENES, CLIMATE, AND WOOD: A STORY OF LODGEPOLE PINE. Gerald E.
Rehfeldt
(grehfeldt@fs.fed.us)
Link to PRESENTATION PROVIDED
Abstract: Analyses of long-term provenance tests of lodgepole pine (Pinus contorta) at 60
environmentally disparate test sites in British Columbia have produced population response
functions driven by climatic descriptors for 20-year height, diameter, survival and,
therefore, volume per ha. The functions demonstrate that populations have different
climatic optima and different growth potentials but tend to occupy suboptimal
environments, with the degree of suboptamility much greater in the north than in the south.
The functions are ideally suited to assessing the impact of changing climates during the
transient phase of vegetal response. This phase presages an approach to equilibrium and
consists sequentially of (1) direct effects on contemporary forests that are governed by the
physiological plasticity of individuals and (2) long-term evolutionary adjustments that
produce the optimal genotypes for the new climates. According to the response functions,
direct impacts of global change on contemporary populations should be highly complex but
largely negative, accruing from the inability of physiologic systems to cope with the
amount of change. In time, the evolutionary process will optimize adaptedness, growth, and
productivity, and, as equilibrium is approached, productivity of the lodgepole pine forests
of British Columbia should increase greatly. This optimistic outlook, however, must be
tempered. The bulk of global climate change is expected to occur in merely a century less
than one generation for lodgepole pine. Yet, quantitative genetic principles suggest that
evolutionary adjustments should take only 3 generations in the north but nearly 12
generations in the south. The transient period, therefore, should last between 300 and 1500
years. The results show clearly that a change in climate will disrupt the genetic system
throughout a species distribution even when changes in the distribution itself are
inconsequential. They also show that the speed of climate change is much more daunting
than the amount of change. Maintaining productive forests during the transient period will
require intensified planting programs designed to assist the evolutionary redistribution of
genotypes.
CHANGING ATMOSPHERIC CONDITIONS
CAMBIOS EN LAS CONDICIONES ATMOSFÉRICAS
EFFECTS OF FORESTRY PRACTICES, INCLUDING CLEARCUT
HARVESTING AND ALTERNATIVE VEGETATION MANAGEMENT
TREATMENTS ON FOREST MICROCLIMATE. Phillip E. Reynolds
(preynold@nrcan.gc.ca)
PRESENTATION PROVIDED
Natural Resources Canada, Canadian Forest Service, Great Lakes Forestry Centre, 1219
Queen St. East, Sault Ste. Marie, Ontario, Canada P6A 5M7
Abstract: The Fallingsnow Ecosystem Project was initiated in northwestern Ontario in
1993 to assess the effects of alternative conifer release practices on ecosystem processes
and components. Treatments included two herbicides, glyphosate and triclopyr applied
aerially at maximum label rates, and two cutting treatments, manually with brushsaws, and
mechanically with a Silvana Selective mower. Treatments were applied to 4 clearcut blocks
(30-60 ha each) harvested between 1986 and 1988, and planted with spruce. Clearcut
controls (5-7 yrs old in 1993) constituted a 5th treatment, and unharvested controls
(approximately 100 yrs old and predominantly aspen, fir, and white birch) adjacent to each
block, constituted a 6th treatment. Study objectives were to quantify treatment-related
microclimatic differences and to assess the duration of these differences. Weather stations,
programmed to continuously monitor photosynthetically-active radiation (PAR), air
temperatures, and relative humidity (RH) at 0.25 and 2.0 m above the forest floor and soil
temperatures at 5 and 15 cm depth, were established from 1994 through 1998. Stations
were deployed on a maximum of 3 blocks, in the clearcut control (C), brushsaw (B),
glyphosate (G), and unharvested forest (F) treatments. epeated measures ANOVA’s were
used to assess treatment differences in 1998 for 2 replicated blocks, 5 years after B or G
treatments, and 12 years after harvesting. nalyses revealed significant treatment differences
for 20 of 22 measured parameters. Lower PAR and higher RH (mean seasonal values for
June 2-October 14 at 2.0 m) were observed for the unharvested forest compared with the
clearcut control. PAR values for the F, C, B, and G treatments were 619, 789, 1629, and
1852 umol . s-1 . m-2, respectively. RH values (daily lows) were 58, 53, 52, and 43%,
respectively. Seasonal air temperature extremes (o C), for daily highs and lows, were
associated with the glyphosate treatment, where non-woody vegetation was dominant.
Temperatures at 2.0 m were 19.9, 21.2, 21.6, and 22.9o, respectively, and 12.7, 11.8, 10.8,
and 10.8o, respectively. Temperatures at 0.25 m were 21.0, 21.8, 23.0, and 26.0o,
respectively, and 11.5, 10.3, 8.5, and 7.8o, respectively. Mean seasonal soil temperatures at
15 cm depth (daily highs) remained highest for the glyphosate treatment, and higher than
for all other treatments. These data suggest that the effects of routine forestry practices in
altering forest microclimate are longer-lasting than anticipated. Changes in forest
microclimate are likely contributing to global warming and to global environmental change.
The extent and significance of these contributions are yet to be determined.
WILDFIRES AND GLOBAL CLIMATE CHANGE ALONG A TRANSECT
THROUGH THE AMERICAS. David V. Sandberg1 and Ernesto Alvarado2
(dsandberg@fs.fed.us) (alvarado@u.washington.edu)
1USDA Forest Service, Pacific Northwest Research Station, Fire and Environmental
Research Applications, 3200 SW Jefferson Way, Corvallis, Oregon 97331 2College of
Forest Resources, University of Washington, Seattle, Washington 98105
Abstract: This paper presents over 25 years of research experience that the Fire and
Environmental Research Applications team of the US Forest Service, PNW Research
Station has been conducting in the boreal, temperate forests, and rangelands of the United
States and Mexico, and tropical ecosystems in Florida, Hawaii, and Brazil. A line drawn
from the tundra of Alaska to the Atlantic forest of Brazil transects virtually all of the Earth's
biomes. This "Transect of the Americas" provides a compact global ecological laboratory
for comparative ecosystem studies; and for testing the rigor of theories across multiple
ecosystems. FERA’s research underlies decision support systems for fire management, air
quality management, and global change response. The applied and theoretical research
conducted by FERA addresses issues that concern to those management and scientific
communities in the United States and elsewhere. Some of FERA products include: tools for
biomass loading and flammability assessment, predicting biomass consumption across
major ecosystems, thermodynamic modeling of smoldering consumption, smoke
management and health assessment tools, and biomass Emissions assessing greenhouse gas
emissions from wildland fires. Since the 70’s, the group has conducted extensive research
on combustion and carbon emissions through North America, Mexico and Brazil that has
lead to the development of combustion algorithms used by fire managers and scientists.
Research in tropical savannas and temperate rangelands is conducive to the development of
equations and methods to evaluate fuelbed characteristics, biomass consumption, air
pollution, and greenhouse gas emissions from fires across environmental gradients.
Flammability and fire severity thresholds are being investigated in the boreal, temperate
forests, and rangelands in the United States, as well as logged and primary Amazon forest.
FERA scientists are responsible for assessing the risk of smoke exposure to the health of
firefighters and rural communities in the United States.
WILDFIRES IN TROPICAL FORESTS. Ernesto Alvarado1 and David V. Sandberg2
(alvarado@u.washington.edu) (dsandberg@fs.fed.us)
1College of Forest Resources, University of Washington, Seattle, Washington 98105
2USDA Forest Service, Pacific Northwest Research Station, Fire and Environmental
Research Applications, 3200 SW Jefferson Way, Corvallis, Oregon 97331
Abstract: Occurrence of catastrophic wildfires in the last few decades in different parts of
the world has raised awareness of devastating local effects, and the potential impact across
international borders. A steady increase of wildfire risk has been detected in temperate
forests of North America, as well as tropical ecosystems of the world. Uncontrollable
wildfires in the tropics are increasing in number and extent at rates higher than temperate
forests. Public is more aware of issues such as biomass burning and greenhouse effects,
loss of natural habitat, international haze and pollution, public health and safety, loss of
industrial and agricultural production, decline in tourism, and increased health care costs.
Ordinarily, undisturbed tropical rain forest is considered a fireproof ecosystem. Severe fire
can only occur during sustained droughts when the ecosystem is dry enough to sustain
smoldering combustion, or when the canopy is disturbed by natural events or human
activities. It is important to anticipate weather and land use patterns that result in high fire
danger so that management and regulatory remedies can be applied. The Spring 1998
wildfire season in Mexico and several other countries across the world signaled how
vulnerable are tropical ecosystems to wildfires and that the immediate effects can be felt
across borders. The land use/land cover classes most extensively impacted in the SE
Mexico were the tall/medium selvas, open/fragmented forests, and perturbed areas. The
estimated total prompt emissions during a two-month period contributed an additional 24%
to the region’s average annual net C emissions from forestry and land-use change. If fire
episodes such as the one that occurred in Mexico and around the world become the norm
due to warmer and drier conditions, then an increase in C emissions may represent a
significant positive feedback to global climate change.
VALIDATING THE INTEGRATED BIOSPHERE SIMULATOR (IBIS) AT
REGIONAL AND LOCAL SCALES IN CANADIAN FOREST ECOSYSTEMS.
Mustapha El Maayar, David Price and Martin Siltanen
(elmaayar@nrcan.gc.ca)
Natural Resources Canada, Canadian Forest Service, Edmonton - Canada
Abstract: The need for improved understanding of ecosystem processes and related
carbon dynamics in response to changes in global climate has led to the construction of
several dynamic global vegetation models (DGVM). Simulations performed with such
models have generally been successful in approximating the distributions and magnitudes
of key ecosystem indicators at the global scale. However, detailed validations against
observations made in different ecosystems at smaller spatio-temporal scales are still highly
desirable. The objectives of this paper address some of these validation requirements. First,
we present and discuss results of site-based simulations of energy, water and carbon fluxes
for different forest stands in central Canada, using the Integrated BIosphere Simulator
(IBIS) of Foley et al (a DGVM). Agreements between observed and simulated energy
balances and CO2 fluxes were generally very good. In a second validation exercise, the
results of a national scale simulation of Canada's forests were compared with a recently
compiled gridded dataset of forest biomass derived from the CFS Canadian Forest
Inventory (CanFI) database. Plant functional types (PFT) used in IBIS were parameterized
to more closely represent the characteristics of Canada's forest vegetation. Simulated
vegetation distribution and biomass densities were found to agree with the gridded dataset
better than were obtained using the global PFT parameterization.
CARBON SEQUESTERING
CAPTURA DE CARBONO
QUANTIFICATION OF SITE- AND SPECIES-SPECIFIC WOOD PRODUCTION
AND CARBON SEQUESTRATION IN RELATION TO CLIMATE CHANGE LODGEPOLE PINE, INTERIOR SPRUCE AND INTERIOR DOUGLAS-FIR.
Cheng C. Ying1 , Gordon Nigh1 , and Hong Qian2
(cheng.ying@gems9.gov.bc.ca), (gordon.nigh@gems2.gov.bc.ca)
(hqian@interchange.ubc.ca)
1
2
B.C. Ministry of Forests, Research Branch, 712 Yates St., Victoria, B.C. V8W 1L4
Department of Forest Science, UBC, Vancouver, B.C. V6T 1Z4
Abstract: Forests as an atmospheric C02 sink or source is still a debated issue. Studies in
recent years have indicated that forests may function as a significant sink, accounting for as
high as 20% of the total carbon budget. These studies are mostly based on the analyses of
satellite image of ground vegetation cover, forest inventories, statistics of wood trade or
model simulations, and at a continental or global scale. Because of its spatial scale,
estimates of sink size varied widely from study to study. High resolution requires site- and
species-specific estimates at regional and local scales. In our study, we used site indexvolume-carbon conversion as the baseline process of quantifying C sequestration. Site
index is a commonly used and reliable predictor of site productivity with regards to stem
wood production. We expect our quantification of C sequestration would result in estimates
with good precision. Our procedure involved 1) refitting the Rehfeldt climate models to
improve the models’ predictability within the sampling range of the three species, 2)
constructing empirical models predicting SI in relation to climate variables in both singleand multi-variate modes, 3) converting SI to volume through the growth and yield model
TIPSY, and 4) calculating C sequestration as C= stem wood volume x wood density x 0.5,
assuming 50% of dry matter is carbon. The process yielded some rather interesting results.
The three species responded very differently to climate change. Lodgepole pine was
sensitive to temperature, but less so to precipitation; correlation coefficients of SI with
temperature-driven climate variables were 0.43 to 0.61, and 0.21 to 0.32 with precipitationdependent variables. On the contrary, interior Douglas-fir was more responsive to
precipitation than to temperature; correlation coefficients of SI with precipitation variables
were 0.32 to 0.73, and 0.23 to 0.38 with temperature variables. Interior spruce was the least
responsive to both temperature and precipitation, correlation coefficients were 0.00 to 0.20.
A temperature increase of 10 C would improve the wood production of lodgepole pine by
1.35 m3/ha/year and C sequestration by 275 kg/ha/year. An increase in annual precipitation
by 100 mm would improve the wood production of interior Douglas-fir by 2.20 m3/ha/year
and C sequestration by 929 kg/ha/year. We have not yet delineated the zone of linear
response along the gradients of temperature and precipitation. As a norm of biological
phenomenon, we expect a detrimental response beyond the linear zone. The above
quantification assumes changing climatic conditions would not alter the basic physiological
mechanism of wood formation.
SOIL CO2 EFFLUX IN RESPONSE TO FERTILIZATION AND MULCHING
TREATMENTS IN A TWO-YEAR-OLD LOBLOLLY PINE PLANTATION IN
THE VIRGINIA PIEDMONT. Robert Pangle and John Seiler.
(rpangle@vt.edu), (jseiler@vt.edu)
Department of Forestry, Virginia Tech
Abstract: In an effort to examine the response of soil CO2 efflux to changes in nutrient
availability, temperature, and moisture, soil respiration rates were measured over an entire
year in a two-year-old loblolly pine (Pinus taeda L.) plantation subjected to fertilization
and mulching treatments. A dynamic, closed-chamber infrared gas analysis system was
used to measure efflux rates from plots treated with one of four treatment combinations
including: nitrogen (115 kg/ha) and phosphorus (11.5 kg/ha) fertilization with black
landscape cloth (mulch), fertilization without mulch, mulch without fertilization, and no
treatment (control). For each treatment combination, plots were established at the seedling
base and 1.22 m away from the seedling base to examine the affect of seedling roots on
efflux rates. Fertilization had no significant effect on efflux rates during any of our monthly
sampling sessions. Rates in plots with mulching were significantly different from nonmulched during some measurement sessions, but differences were inconsistent and often
could not be attributed to temperature or moisture differences in mulched plots. Rates at the
seedling base were always significantly higher than rates in plots away from the seedling.
Although rates were always higher at the seedling base, the variability observed did not
correlate with the amount of pine roots present beneath respiration chambers. Average
efflux rates ranged from a high of 2.39 mol/m2/s in July to a low of 0.142 mol/m2/s in
January. Utilizing environmental, soil, and plant variables in a regression model explained
51.4 % of the variance in soil CO2 efflux rates. Soil temperature alone explained 42 % of
the variance followed by soil moisture and stem biomass at 3.2 % and 2.8 % respectively.
Only an additional 3.4 % of the variance was explained by a large number of other factors
such as coarse woody debris, soil coarse fragment %, and fine root biomass.
THE EFFECTS OF PLANTING DENSITY ON CARBON PARTITIONING
BETWEEN FINE ROOTS, LEAF BIOMASS AND STEM GROWTH. Colter Burkes,
Rodney E. Will and Robert O. Teskey
Abstract: The effect of stand density (740, 2220 and 3700 trees per hectare) on growth and
dry matter partitioning was examined in four-year-old loblolly (Pinus taeda L.) and slash
pine (P. elliottii Engelm.) in four intensively managed plantations in southern Georgia. In
the third and fourth growing seasons stem biomass growth did not increase proportionally
with density but in a curvilinear fashion. The ratio of leaf biomass: stem biomass growth
was significantly greater for loblolly pine stands planted at 740 trees ha-1 compared to the
other densities. There was no difference between the stands planted at 2220 and 3700 trees
ha-1. This indicated that growth efficiency of the lowest spacing was significantly lower
than the other two spacings. Density had the same effect on the ratio of fine root biomass:
stem biomass growth as on the leaf biomass: stem growth ratio for both species. Therefore,
less fine root biomass was necessary per unit stem growth at the two higher stand densities.
Density had no effect on the ratio of fine root biomass: leaf biomass for both species
indicating a constant partitioning between fine root and leaf biomass at different densities.
However, the fine root: leaf area index ratio was greater in slash than loblolly pine due to
the lower specific leaf area of slash pine. These results indicate that partitioning to stem
growth does not decrease with increasing density, rather partitioning to stem growth is
lower at the lowest stand density due to increased partitioning to fine root growth.
RECALCITRANT SEED & GERMPLASM CONSERVATION
SEMILLA RECALCITRANTE Y CONSERVACIÓN DE GERMOPLASMA
GERMINATION OF CO2 ENRICHED Pinus taeda L. SEED AND SUBSEQUENT
SEEDLING GROWTH RESPONSES TO CO2 ENRICHMENT. Mark E. Kubiske1 ,
Manzoor Hussain1, Kristina F. Connor2
(mkubiske@cfr.msstate.edu)
1Department of Forestry, Mississippi State University 2USDA Forest Service, Center for
Bottomland Hardwoods Research
Abstract: To understand the combined effects of seed production and seedling growth
under elevated atmospheric CO2, we collected Pinus taeda L. seed that developed in
ambient or elevated (ambient + 200 ppm) CO2 environments and germinated them in
ambient and elevated CO2 greenhouse chambers. The seedlings were allowed to grow
under treatments for 121 d in pure sand without the addition of nutrients to determine the
effect that seed reserves might have on seedling growth. Seeds that developed in elevated
CO2 had 91% greater weight and 265% greater lipid content than those that developed in
ambient CO2. The elevated seed source also had three times the germination success, and
germinated up to 5 d earlier compared to the ambient seed source, regardless of greenhouse
chambers. There were few significant seedsource or treatment effects on seedling growth,
although the elevated seed source tended to produce seedlings that were taller and had more
needles, greater root length, and higher root and leaf N concentrations compared to the
ambient seed source. Carboxylation efficiency of the seedlings was significantly reduced by
growth in elevated CO2 suggesting that the nutrient-poor conditions had a significant effect
on the CO2 growth responses. We concluded that Pinus seeds produced in a CO2-enriched
environment may have fundamental changes in their viability and germination. Growth
characteristics of new germinants may affect subsequent tree development and measurable
responses to elevated CO2.
STATUS OF BUR OAK (Quercus macrocarpa) IN NEW BRUNSWICK, CANADA
AND IMPLICATIONS FOR GENE CONSERVATION. D.A. McPhee and J.A. Loo
Canadian Forest Service, Atlantic Forestry Centre, P.O. Box 4000, Fredericton, New
Brunswick E3B 5P7 CANADA
Abstract: The natural range of bur oak extends from eastern Canada to the mid-west and as
far south as Texas. In the central part of its range the species is under no threat, but the
eastern-most populations are small and isolated. In maritime Canada, published range maps
depict the species extending only along the Saint John River and around the Grand Lake
region in the province of New Brunswick. Today however, this range has shrunk and
remaining small populations are physically isolated from the contiguous range by
approximately 750 km. A study conducted to examine the current distribution and genetic
status of the New Brunswick populations, determined that aside from individual trees or
small clumps, only eight stands of bur oak remain in the province. Of these only one has
more than 500 mature trees. Genetic diversity of these stands, other isolated stands in
eastern U.S. and populations on the fringe and within the contiguous range was examined
using isozyme analysis. Data from 19 isozyme loci indicate that the New Brunswick
populations have retained high levels of genetic diversity, similar to populations within the
species contiguous range. Though the small populations are threatened by increasing land
use pressures, prompt conservation action, including maintaining existing stands and using
local seed for restoration plantings, should be effective. It is considered important to
maintain the species in New Brunswick because of its potential ecological significance with
the expectation of a warmer climate.
BIOLOGICAL RESPONSE TO CHANGE
RESPUESTA BIOLÓGICA AL CAMBIO
EFFECTS OF ELEVATED CO2 AND TEMPERATURE ON THE RESPONSE OF
PONDEROSA PINE TO OZONE: A SIMULATION ANALYSIS. David T. Tingey1,
John Laurence2, James A Weber1, Joseph Greene1, William E. Hogsett1, Sandra
Brown3 and E. Henry Lee1
(dtingey@mail.cor.epa.gov), (jal6@cornell.edu), (greenej@mail.cor.epa.gov),
(bill@mail.cor.epa.gov), (Sbrown@winrock.org) and (henry@mail.cor.epa.gov)
1
U.S. Environmental Protection Agency, Western Ecology Division, Corvallis, OR 97333
Boyce Thompson Institute for Plant Research, Ithaca, NY 14853 3Winrock International,
Corvallis OR 97330
2
Abstract: Forests regulate numerous biogeochemical cycles, storing and cycling carbon,
water, and nutrients, however, there is concern how climate change, elevated CO2 and
tropospheric O3 will affect these processes. We investigated the potential impact of
increased O3 in combination with projected climate and atmospheric CO2 concentrations on
growth of Pinus ponderosa, at 7 sites in California, Oregon, and Washington, USA, using
TREGRO, a process-based whole-tree growth model. The model provides a tool to study
interactions among various factors and processes that give rise to synergistic responses.
Simulated plant growth increased proportional to CO2 concentration, however, the
magnitude of the growth increase varied among sites as other factors influenced response.
Increasing air temperature (+1.3 C) increased growth at most sites. Elevated CO2 increased
the temperature optimum for growth at 4 sites and decreased it at 2 sites. The annual
biomass increment decreased with increasing O3 exposure. The differences in O3 sensitivity
among sites is primarily controlled by differences in precipitation. Simulations indicate that
increasing levels of tropospheric O3, changing climate and rising atmospheric CO2 can alter
the C sequestrating potential of forests. Although increasing CO2 reduces O3 sensitivity, it
does not eliminate the impact of O3; elevated CO2 would enhance C storage in forests more
if O3 exposures were reduced, especially in more polluted sites. Although the greatest
benefit in C storage will come from reducing O3 exposures in the most polluted sites, we
must also consider those sites that have high inherent O3 sensitivity because of their mesic
conditions. Limiting the increase of O3 levels in those areas will also increase C storage in
forests. In contrast, C storage in other areas, that have a lower inherent O3 sensitivity would
likely not be as impacted by increasing O3 exposures as the plants are climatically less
sensitive to O3.
EFFECTS OF WATER STRESS ON WATER POTENTIAL AND STOMATAL
CONDUCTANCE OF FOUR Pinus SPECIES. Eladio H. Cornejo-Oviedo1 and
William Emmingham2
(cor61@prodigy.net.mx) and (emminghamw@fsl.orst.edu)
1Departamento Forestal. División de Agronomía. Universidad Autónoma Agraria “Antonio
2312 Richardson Hall,
Narro.” Buenavista, Saltillo, Coahuila. México. C.P. 25315
Department of Forest Science, College of Forestry, Oregon State University, Corvallis,
Oregon USA 97331-5752
Abstract: In a greenhouse study, we investigated the response of water relations of
seedlings of Arizona pine (Pinus arizonica Engelm.), Apache pine or pino real (Pinus
engelmannii Carr.), Durango pine (Pinus durangensis Mart.), and Ponderosa pine (Pinus
ponderosa Laws.) subjected to stressing treatments. The two treatments were well-watered
and water-stressed, conducted over three replicated drying cycles during the dormant
season. The well-watered treatment ranged between 67 and 36% of volumetric water
content of the growing media; the water content in media of the stress treatment ranged
between 8.0 and 2.0% of volumetric water content. Due to inherent species differences in
morphology and physiology, the level of water stress at the end of the drying cycles was
not the same for all species. Xylem water potential and stomatal conductances were
measured in needle fascicles at the ends of two drying cycles. Water stress caused
significant and highly significant treatment and diurnal differences in plant water relations
in at least three of the species during those two cycles. At midday, stomatal conductance
was reduced significantly (by more than 60%) in the water-stress treatment. For each
species, a maximum midday stomatal-conductance value was defined, based on the mean
and standard deviation of midday conductance in the well-watered treatment over the three
drying cycles. This maximum value was used as the baseline (100%) from which relative
values were estimated for conductance readings in the well-watered and water-stress
treatments. For each species, we identified a predawn water potential range associated with
less than 50% of the maximum midday stomatal conductance.
DEEP ROOT GROWTH OF LOBLOLLY PINE IN RESPONSE TO THROUGHFALL
EXCLUSION. Mary Anne Sword1 and Zhenmin Tang2
(msword@fs.fed.us) and (zmtang@attglobal.net)
1
USDA Forest Service, Southern Research Station, Pineville, LA 71360, USA, 2School of
Forestry, Wildlife, and Fisheries, Louisiana Agricultural Experiment Station, Louisiana
State University Agricultural Center, Baton Rouge, LA 70803, USA
Abstract: Deep root growth is needed to maintain physiological activity as water
availability decreases. The objective of this study was to evaluate relationships between
root growth and available water to a 1 m depth and tree physiology across a range of soil
water availabilities. Plastic tarps were used to exclude throughfall in a 19-year-old loblolly
pine plantation. The soil environment, root growth and fascicle physiology of eight
dominant trees were monitored during the 1999 growing season. The soil profile to a 1 m
depth was partitioned into four texturally distinct increments and soil water content in each
was quantified daily by time domain reflectometry. Moisture release curves were
developed to express soil water content as available water. Root initiation by depth was
measured in vertical Plexiglas rhizotrons. Twice each month, predawn water potential and
physiology of upper crown fascicles were measured three times daily. Drought during
1998 and 1999 was associated with a 37 percent decrease in predawn water potential during
the 1999 growing season when compared to the average of four previous non-drought years
(1993-1996). Both shallow (0-20 cm) and deep (56-100 cm) root initiation were reduced
by throughfall exclusion. During July and August, stomatal conductance and net
photosynthesis at 1300 and 1500, but not at 1100, were limited by elevated air temperature
and vapor pressure deficit. Physiological processes at 1100 were not related to shallow
available water; however, stomatal conductance and net photosynthesis at 1100 were
positively correlated with available water at the 33 to 56, 56 to 100 and 33 to 100 cm
depths. We also observed significant but weak positive relationships between physiological
activity at 1100 and root growth at all depths. Before daily atmospheric limitations to
physiology occurred, physiological processes appeared to be a function of deep available
water and root growth throughout the soil profile. However, available water and root
growth responses to throughfall exclusion indicated that the spatial variation associated
with soil properties that control water retention and root advancement was high. At our
study site, therefore, stand-level prediction of physiological activity may require
information on the spatial variability of soil physical properties that affect the availability
of water and the depth of the root zone.
ENVIRONMENTAL INFLUENCES ON GAS EXCHANGE IN FERTILIZED AND
NON-FERTILIZED LOBLOLLY PINE STANDS. Christopher Gough1, John Seiler1,
Kurt Johnsen2
(chgough@vt.edu), (jseiler@vt.edu)
1
Department of Forestry, Virginia Tech
Station
2
United States Forest Service Southern Research
Abstract: Spatial and temporal variation in foliar gas exchange was examined in 15-yearold fertilized and non-fertilized loblolly pine stands located in the North Carolina sandhills.
Foliar gas exchange in both the upper and lower thirds of crowns for both fertilized and
non-fertilized stands was monitored monthly for a year beginning in March 1999 using an
open gas exchange system. Monthly measurements consisted of morning, early afternoon,
and late afternoon measurement periods taken during a single day. Gas exchange rates were
recorded for a single detached fascicle at ambient temperature, humidity, vapor pressure
deficit, and at a constant CO2 concentration of 350 ppm. Average photosynthetically active
radiation was determined for the upper and lower thirds of crowns and kept constant for
each crown level in the block during a measurement period. Mean photosynthesis between
fertilization treatments was statistically different for only three months: February, April,
and May (p<.1). In February, fertilized stands exhibited higher photosynthesis rates while
in April and May non-fertilized stands had higher photosynthesis rates. Photosynthesis
rates were greater in the upper third of the crown compared to the lower third of the crown
for all months. Empirical models were developed to estimate carbon uptake and compare
response surfaces among treatments and seasons. Statistical comparisons of parameter
estimates reveal that foliage from the upper third of the crown in both fertilized and nonfertilized stands have higher predicted respiration rates and exhibit greater responsiveness
to light compared to the lower third of the crown. Prediction models also show that foliage
from fertilized stands is more sensitive to vapor pressure deficit than foliage from nonfertilized stands. Foliage during the growing season appears to be more responsive to light
compared to foliage during the non-growing season. Other trends in seasonal gas exchange
will be discussed with an emphasis on carbon uptake.
CARBON DIOXIDE CONCENTRATIONS IN TREE STEMS AND THEIR
EFFECT ON APPARENT STEM RESPIRATION. Robert O. Teskey and Mary Anne
McGuire
(rteskey@arches.uga.edu)
Warnell School of Forest Resources, University of Georgia, Athens, GA 30602 USA
Abstract: We used microelectrodes placed in tree stems to measure the carbon dioxide
(CO2) concentrations in the stems over time. Measurements were made on small, medium
and large diameter trees of three species, yellow-poplar (Liriodendron tuliperfera, L.),
white oak (Quercus alba, L.) and loblolly pine (Pinus taeda, L.) during the summer at a
field site near Athens, Georgia, USA. The trees ranged from 14 to 72 cm in diameter at
1.5m, and were growing in the same stand. Carbon dioxide concentrations in the stems
fluctuated over time in the range of 2 to 10%. The CO2 concentrations were similar in all
species, and similar among trees in the three diameter classes. Diurnal changes in CO2 were
clearly evident and were correlated with the rate of water movement through the xylem, as
measured by thermal dissipation sap velocity probes placed near the CO2 microelectrodes.
Using cut branches of these species in the laboratory, we were able to demonstrate that the
rate of CO2 efflux from the branch directly depended on the concentration of CO2 in the
xylem sap, which we experimentally manipulated over a range of 1 to 10%. Using an
infrared gas analyser, stem CO2 efflux was measured in the field. Efflux varied diurnally
and was directly correlated with xylem CO2 concentration measured with the
microelectrodes. The results from these experiments indicate that previous estimates of
stem respiration made using measurements of carbon dioxide concentrations, such as those
obtained with infrared gas analyzers, are incorrect. Carbon dioxide efflux from tree stems
appears to be mostly a function of the concentration of CO2 in the xylem sap and the rate of
diffusion of CO2 from the stem.
LEAF BIOCHEMICAL CHANGES INDUCED IN Populus trichocarpa BY
ENHANCED UV-B RADIATION AND CONCOMITANT EFFECTS ON
HERBIVORY BY Chrysomela scripta (Colepoptera: Chrysomelidae). Jeffrey M.
Warren and John H. Bassman.
(jmwarren@mail.wsu.edu) and (bassman@mail.wsu.edu)
PRESENTATION PROVIDED
Department of Natural Resource Sciences, Washington State University, Pullman, WA
99164-6410, USA
Abstract: Glasshouse-grown Populus trichocarpa Torr. & Gray (black cottonwood) were
subjected to none (0X), ambient (1X) or twice ambient (2X) levels of biologically effective
UV-B radiation for Pullman, WA, USA in a randomized block design. Supplemental UV-B
radiation was supplied over a 10 h period centered on solar noon using UVB 313 lamps (QPanel Co., Cleveland, OH, USA) mounted in frames suspended above the pots and filtered
with polyester (0X - removes <315 nm) or cellulose diacetate (1X, 2X - removes <300
nm). Different treatments were obtained by varying the distance between lamps and the
plant canopy and monitored using a spectroradiometer (Optronics Laboratories, Orlando,
FL, USA). After a 10-week treatment period, an ontogenetic series of leaves were sampled.
Apparent photosynthesis was determined in situ using 14CO2. Subsamples were analyzed
for nutrients (C, N, S), chlorophylls, UV-absorbing compounds, tannins and specific
flavonoids. Effects of changes in leaf biochemistry on feeding by a major cottonwood
herbivore, Chrysomela scripta Fab. (cottonwood leaf beetle), were determined in two ways:
(1) a choice or preference test where the third (final) instar was presented foliage samples
from each treatment; and (2) evaluation of larval growth rates fed tissue samples from each
treatment. There was strong ontogenetic separation of treatment effects; significant
differences in leaf biochemistry were seen in LPI2, becoming progressively less
significant as the leaves aged. Apparent photosynthesis increased with increased levels of
UV-B radiation, coinciding with higher levels of chlorophylls. Enhanced UV-B radiation
also increased production of leaf proteins (as increased N and S concentrations), flavonoids,
and changed flavonoid composition. The 2X treatment caused higher levels of UVabsorbing compounds than the 1X treatment, but tannins were reduced with increased UVB radiation. Larvae showed higher preference for, and had higher growth rates when fed
foliage from the 2X treatment compared to the 1X or 0X treatments. Tissue palatability
appears linked to UV-B-induced changes in foliar nutrient composition and protein-binding
tannins. Results suggest that enhanced UV-B radiation induces shifts in carbon allocation
resulting in altered foliar biochemistry conducive to increased levels of herbivory.
PHYSIOLOGICAL RESPONSES OF FIELD-GROWN LOBLOLLY PINE TO
SUMMER DROUGHT. Zhenmin Tang1 , Jim L. Chambers1 , Mary Anne Sword2 ,
and James P. Barnett2
(zmtang@attglobal.net), (jchamb@lsu.edu), (msword/srs_pineville@fs.fed.us) and
(barnett_james/srs_pineville@fs.fed.us)
1
School of Forestry, Wildlife, and Fisheries, Louisiana Agricultural Experiment Station,
Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA 2 USDA
Forest Service, Southern Research Station, Pineville, LA 71360, USA.
Abstract: Gas exchange variables of current-year first-flush foliage were recorded in a 14year-old loblolly pine plantation (Pinus taeda L.) from July through September in 1995 (a
wet year) and 1998 (a dry year) to contrast year-to-year differences in leaf carbon
assimilation and water relations as impacted by summer drought. Diurnal measurements
were taken four times each day (0900, 1100, 1300 and 1500 h) on sunny days (at least three
days each month during the two summers). Physiological data were collected in the upper
and lower tree crowns under field conditions. A severe drought occurred during the summer
of 1998 and the amount of rainfall was only 35 mm in July, which represents 41% of the
July rainfall in 1995. Mean predawn leaf pressure potential and stomatal conductance were
substantially lower in July of the dry year than in the same month of the wet year. Mean net
photosynthetic rate and transpiration (per unit leaf surface area) in July were also
drastically lower in the dry year versus wet year. Low gas exchange continued through
August in the dry year due to the prolonged drought effect. In contrast, net photosynthesis
and stomatal conductance were significantly higher in September of dry 1998 than in the
same month of wet 1995, because rainfall was substantially higher, while leaf temperature
and leaf-to-air vapor pressure deficit were lower in September of the dry year. Predawn
xylem pressure potential was significantly correlated with net photosynthesis and
transpiration during the summer months (r = 0.66 and 0.56, respectively). A close
relationship between stomatal conductance and net photosynthesis (r = 0.84) suggests that
summer drought may greatly affect leaf gas exchange by strong stomatal limitations to CO2
uptake. Implications of our findings for potential impacts of global climate change on
southern pine forests will be discussed.
A COMPARISON OF SOIL TEMPERATURE EFFECTS ON GROWTH AND
PHYSIOLOGY IN WHITE SPRUCE (Picea glauca) AND ASPEN (Populus
tremuloides). Simon M. Landhausser and Victor J. Lieffers
(Simon.Landhausser@ualberta.ca)
4-42 Earth Sciences Building, Department of Renewable Resources, University of Alberta,
Edmonton, Alberta, T6G 2E3, Canada
Abstract: Low soil temperatures are a common feature in the boreal forest and are a key
factor in limiting tree growth, especially on sites with thick layers of organic matter. White
spruce (Picea glauca (Moench) Voss) and aspen (Populus tremuloides Michx.) are the two
major components of the boreal mixedwood forest of western North America. We
hypothesize that white spruce, because of its later successional status, possesses adaptations
which makes it less sensitive to cold soil temperatures than aspen. The objective of this
growth chamber study was to compare the physiological and morphological response of
aspen and white spruce seedlings to different soil temperatures (5, 15 and 25 C) during the
growing and dormant season. Aspen responded very strongly to low soil temperatures by
reducing leaf area and shoot and root growth. In white spruce, first year above-ground
growth was not significantly affected low soil temperatures. While at 5C soil temperature,
there was virtually no root growth in aspen, white spruce increased its root mass by about
10%. The dormant season measurements showed that root mass in both species increased
from the growing season measurement while root volume remained constant. The exception
were aspen roots grown at 5C which did not show an increase in root mass during the
dormant season. Net assimilation and stomatal conductance in aspen was significantly
reduced with decreasing soil temperatures, while in white spruce these physiological
variables were not affected by low soil temperatures. Total non-structural carbohydrates
reserves were significantly higher in aspen during the growing seasons in all plant parts
than in the dormant season; these differences were not apparent in white spruce. The results
of this study showed that spruce is capable of functioning more efficiently under low soil
temperatures than aspen. The results could have important implication for the interpretation
of successional pathways in northern boreal mixedwood systems.
EFFECT OF DIFFERENT DAY-TIME AND NIGHT-TIME TEMPERATURE
REGIMES ON THE FOLIAR RESPIRATION OF Pinus taeda; PREDICTING THE
EFFECT OF VARIABLE TEMPERATURE ON ACCLIMATION. Rodney Will
(rwill@arches.uga.edu)
Warnell School of Forest Resources, University of Georgia, Athens, GA 30602, USA
Abstract: The objectives of this study were to determine the acclimation of loblolly pine
(Pinus taeda L.) foliar respiration to different night-time low temperatures, day-time high
temperatures, and daily mean temperatures, and then to use the responses of temperature
acclimation to various temperature regimes to predict acclimation under fluctuating
temperatures. Experiments were conducted on two-year-old seedlings in growth chambers
using different combinations of day- and night-time temperatures. The first experiment
exposed trees to 22/22, 29/22, 22/15, and 29/15oC day/night. When measured at a common
temperature (15, 22, or 29oC), respiration rates were lower for trees exposed to higher
treatment temperatures and acclimation was influenced by both day- and night-time
temperature. However, the extent of acclimation did not relate to mean temperature, i.e.,
respiration rates measured at a common temperature ranked as follows for seedlings
exposed to different temperature regimes, 22/15 d/n > 22/22 d/n > 29/15 d/n  29/22 d/n.
Rather, acclimation of foliar respiration was linearly related to mean daily respiration rate,
where mean daily respiration rate is the average of the respiration rates measured at the
day- and night-time treatment temperatures. The discrepancy between mean daily
respiration rate and mean daily temperature occurred because respiration increased
exponentially with increasing temperature. In a second experiment, the same seedlings
were exposed to 22/22, 15/15, 25.5/18.5, and 25.5/15oC day/night to test the relationship
between mean daily respiration rate and acclimation. As in the first experiment, acclimation
was linearly related to mean daily respiration rate. The concept of effective acclimation
temperature, which is the temperature at which the mean daily respiration rate occurs, was
derived from these results as a means to predict the extent that foliar respiration acclimates
to treatment temperature.
ROOT BIOMASS AND SOIL CO2 EFFLUX OF MID-ROTATION LOBLOLLY
PINE EXPOSED TO ELEVATED CO2 AND FERTILIZATION. K.H. Johnsen, L.W.
Kress, J.R. Butnor and C.E. Maier
(kjohnsen@fs.fed.us), (lkress@fs.fed.us), (jbutnor@fs.fed.us) and (cmaier@fs.fed.us)
Southern Research Station, USDA Forest Service, 3041 Cornwallis Road, Research
Triangle Park, NC 27709, USA
Abstract: We exposed 13-year-old loblolly pine trees to two levels of atmospheric CO2
under a high and low nutrient regime and then assessed root biomass quantity and
distribution, as well as soil CO2 evolution. The trees were part of a 2 x 2 factorial
fertilization and irrigation study at the Southeast Tree Research and Education Site
(SETRES) located in Scotland County, North Carolina. Whole-tree, open-top chambers
were used to expose trees to ambient or ambient plus 200 ppm CO2; exposure lasted from
August, 1996 through February, 1999. The tank CO2 was depleted in 13C, relative to
atmospheric CO2, and resulted in the foliage of elevated CO2 trees having a δ 13C of –42.91,
compared to –29.05 for ambient CO2 trees. This 13C signature allowed us to quantify the
spatial distribution of individual tree root systems through the stand. During February,
1999, we sampled at a frequency proportional to area (using a soil core down to 1 m), at 1
m intervals to a 7 m horizontal distance from the base of each tree. Cores were stratified to
three depths, roots were sorted into 3 size classes, dried and weighed and then analyzed for
13 12
C: C ratio. There was no difference in root biomass between the two CO2 treatments.
Fertilizer treatments differed greatly in root biomass; there were 18% less fine roots (<2
mm), and 58% more coarse roots (>2 mm), in fertilized versus non-fertilized plots,
respectively. Elevated CO2 grown trees roots 1 m from the tree stem did have a decreased δ
13
C, relative to control trees and this 13C signature was apparent, on average, up to 5 m
away from the trees. Soil CO2 efflux was assessed at 1.6 and 2.6 m from the base of each
tree using an automated carbon efflux system. Similar to root biomass results, there was no
difference in soil CO2 efflux between CO2 treatments. Although, fertilized trees had, on
average, 37% more below-ground biomass, they also did not differ in soil CO2 efflux
compared to non-fertilized trees. Thus, forest fertilization might be an effective way to
increase below-ground C sequestration in southern pine plantations.
VEGETATION RESPONSE & CLIMATE CHANGE
RESPUESTA DE LA VEGETACIÓN Y CAMBIO CLIMÁTICO
NATURALLY REGENERATED LONGLEAF PINE SEEDLING DYNAMICS IN A
CHANGING CLIMATE. Anne Carraway
(carrarway@forestry.auburn.edu)KL
Auburn University, 108 M. White Smith Hall, Auburn, AL, 36849
Abstract: Significant climate change is expected to occur during this century due to
warming caused by increasing CO2 in the atmosphere. One of the major changes expected
will be substantial change in the range limits of many tree species, concomitant changes in
species composition and importance in forest communities. Longleaf pine (Pinus palustris
Mill.), which once dominated the southern forests, has now been severely reduced in range.
However, the significant loss of longleaf pine acreage has not changed its regional
distribution. It is an excellent source of timber as well as the dominant species of a highly
diverse fire maintained ecosystem. Longleaf pine stands cover some 1.3 million ha in the
southern United States of which 1.18 million ha (91%) support natural stands and contain
94% of the species' growing stock volume. It is imperative to understand what site
conditions in natural stands will ensure the survival of seedlings. While it is known how
site conditions affect the growth of seedlings, the relationship between site characteristics
and seedling mortality has not been well documented. Recent research efforts in south
Alabama, USA examined naturally regenerated longleaf pine seedling mortality. It is with
this research that we intend to make available to landowners and industries alike a tool for
predicting seed crop fate of naturally regenerated longleaf seedlings. Because of its broad
geographic range and wide variety of habitats (climate niche), longleaf pine should be well
suited to adjust to possible changes in climate. With concerns over increasing CO2 and the
need to retain carbon on site, longleaf pine is the best-suited southern pine for longer
rotations.
THE INFLUENCE OF ELEVATED TEMPERATURE ON BIOMASS
ALLOCATION AND FOLIAR RESPIRATION IN JACK PINE (Pinus banksiana
Lamb.) AND PITCH PINE (Pinus rigida Mill.) Schedlbauer, J.L. Day, M.E., and
Livingston, W.H.
(jessica_schedlbauer@umenfa.maine.edu)
Department of Forest Ecosystem Science, University of Maine, Orono, ME 04469
Abstract: Jack pine (Pinus banksiana) and pitch pine (Pinus rigida) meet at their
respective southern and northern range limits in a narrow band in Maine. Although the
ranges of these species are quite different, both have similar site requirements. If climate is
involved in limiting the ranges of jack pine and pitch pine, it is possible that an increase in
temperature associated with global climate change will induce a shift in the current ranges
of these species. Our objective was to determine whether jack pine, a cold adapted species,
responded negatively to elevated temperature relative to pitch pine. Three-year-old jack
pine and pitch pine seedlings were exposed to night temperatures ~5C higher than ambient
conditions to examine the effect of elevated night temperatures on biomass allocation.
Photosynthetic and foliar maintenance respiration rates of the two species were also
studied. Measurements of photosynthesis made on current year foliage did not differ
significantly between species. Respiration rates of jack pine and pitch pine on both mass
and area bases did not significantly differ over a range of temperatures and therefore, both
species had similar Q10 values. The species did not differ in their response to elevated night
temperatures in terms of aboveground, belowground, or total biomass. However, pitch pine
consistently had a significantly greater total needle mass than jack pine, and the species
responded differently, in terms of shoot-to-root ratios, to the elevated night temperature
treatment. These differences in allocation may make pitch pine a superior competitor and
may permit to extend the northern boundary of its range at the expense of jack pine as
global climate change progresses.
15-YEAR HEIGHT OF Pinus ponderosa IS CORRELATED WITH DIURNAL
TEMPERATURE VARIATION DURING BUD ELONGATION. John N. Church, 1,
Richard S. Criddle, 2 and Lee D. Hansen, 3
(jnchurch@ucdavis.edu), (rscriddle@ucdavis.edu) and (ldhansen@chemdept.byu.edu)
1Agricultural and Environmental Graduate Group, Department of Environmental
Horticulture, University of California, One Shields Avenue, Davis, CA, USA, 95616
2Section of Molecular and Cellular Biology, University of California, One Shields Avenue,
Davis, CA, USA, 95616 3Department of Chemistry and Biochemistry, Brigham Young
University, Provo UT, USA, 84602
Abstract: An inverse correlation exists between mean diurnal temperature variation (DT)
during the bud elongation season and the 15-year height of Pinus ponderosa. Environments
with larger DT result in slower growth rates than environments with smaller DT for all
families tested. The coefficient of determination (R2) for the mean height of 17 open
pollinated families was 0.99. Comparable R2 of 0.90 and 0.93, respectively, were found for
local trees (same seed zone and similar elevation as the plantations) and general trees (same
seed zones but not necessarily similar elevations). In contrast, R2 for mean local tree height
correlation with the more commonly considered variables of elevation, latitude, mean
temperature, and mean daily high temperature for the warmest month of the year were 0.46,
0.73, 0.57, and 0.19, respectively. The available data indicates that the strong correlation
between DT and growth rate can be used to select for site fitness, growth rates on untested
sites, and adaptation of a species to a site, and to predict the response to climate change.
The strong correlation between growth season temperatures and growth rates may be more
effective than using geography and elevation in definition of seed and breeding zones.
POTENTIAL IMPACT OF CLIMATIC CHANGE ON GROWTH AND WOOD
QUALITY IN WHITE SPRUCE. Christophe Andalo1,2, Jean Beaulieu1 & Jean
Bousquet2
PRESENTATION PROVIDED
1
Natural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du
P.E.P.S., P.O. Box 3800, Sainte-Foy, Québec, Canada G1V 4C7 2 CRBF, Université
Laval, Sainte-Foy, Québec, Canada G1K 7P4
Abstract: Forest tree species growing in eastern Canada are expected to be highly affected
in the near future by global climatic changes. To mitigate the negative impacts on forests, a
better knowledge of the response of tree species to climatic change must be acquired. In
this study, we used data collected in a provenance-progeny test of white spruce [Picea
glauca (Moench) Voss] including 41 provenances originating from the province of Québec
(Canada), each represented by four open-pollinated families. The test was replicated on
three different sites. In contrast with previous works, we considered several important traits
such as height growth and wood density which are known to be negatively correlated at the
phenotypic level and unrelated at the genetic level. Polynomial regression models were
developed to predict provenance performance, based on temperature and precipitation
differentials (and more generally on climatic differentials) between experimental site
locations and provenance origins. Global climatic models predict an increase of
temperature and precipitation in the near future for eastern Canada. Our results showed, for
all the traits studied, that such rapid environmental disturbance would produce a decrease in
performance relative to a locally adapted seed source. However, the general response
patterns to climatic variation for height growth and wood density were completely different
one from each other. These models were validated using data collected in a second
provenance-progeny test series based on provenances present in both series as well as on
provenances tested only in the second one. These results showed the complexity of tree’s
response to climatic change, which could not be properly assessed without a multivariate
approach. The models will be used to identify the best adapted white spruce seed sources
for reforestation in the new growth conditions induced by global warming.
GENETICS AND FOREST TREE IMPROVEMENT
GENÉTICA Y MEJORAMIENTO DE ÁRBOLES FORESTALES
FOREST MANAGEMENT IMPACTS ON THE GENETIC DIVERSITY OF
EASTERN HEMLOCK. G.J. Hawley1 , D.H. DeHayes1 and J.C. Rrissette2
(ghawley@nature.snr.uvm.edu), (ddehayes@nature.snr.uvm.edu) and (jbrissette@fs.fed.us)
1School of Natural Resources, University of Vermont, Burlington, VT, U.S.A., 05405
2U.S.D.A. Forest Service, Northeastern Research Station, Durham, NH, U.S.A., 03824
Abstract: Genetic diversity assessments were conducted on eastern hemlock (Tsuga
canadensis (L.) Carr.) trees resulting from active silvicultural experiments in Maine, U.S.A.
Treatments include fixed diameter limit cuts (in 1952, 1973 and 1994) which removed trees
24 cm or larger and selection cuts (in 1957 and 1977) which removed inferior,
unmerchantable and poor risk trees. Stand-level genetic diversity estimates were obtained
for stands representing each silvicultural treatment using starch-gel electrophoresis and
were compared to estimates for an unmanaged control stand to estimate genetic changes
resulting from these long-term silvicultural treatments. Compared to genetic estimates for
the unmanaged control stand, a series of selection cuts have had limited impact on the level
of genetic diversity in the residual stand. However, there was a loss of rare alleles that may
be valuable for future evolution. Trees remaining after repeated diameter-limit cuts had
significantly higher levels of heterozygosity, polymorphic loci, and effective number of
alleles per locus. These counter-intuitive results reflect an apparent association between
rare alleles and defective phenotypes. Several alleles that occurred at very low frequencies
in the unmanaged control stand occurred at much higher frequencies in the diameter limit
cut because the defective residual trees preferentially possessed these rare alleles. That is,
rare alleles conferred a negative fitness impact. If rare alleles are disadvantageous, there
may be a loss of fitness in the diameter limit stand compared to the unmanaged stand.
Because residual trees in the selection cut stand contained fewer rare alleles than the control
stand, there may be an increase in fitness resulting from repeated selection cuts, at least in
the short term. However, in the long term this loss of rare alleles in the selection cut
compared to the control stand may come at an evolutionary cost because rare alleles are the
raw material for evolutionary change.
EVOLUTIONARY RELATIONSHIPS OF SLASH PINE (Pinus elliottii) WITH ITS
TEMPERATE AND TROPICAL RELATIVES. R.C. Schmidtling and V. Hipkins
(SCHMIDTL@datasync.com)
1
USDA Forest Service, SRS, Southern Institute of Forest Genetics, 23332 Hwy 67, Saucier,
MS 39574, USA 2 USDA Forest Service, NFGEL Lab., Placerville, CA, USA
Abstract: Allozymes in bud tissue and monoterpene contents in xylem oleoresin of slash pine
(Pinus elliottii) were analyzed from populations across the natural distribution, as well as those
from other species in the AUSTRALES pines. Allozyme diversity measures of slash pine
were similar to those found in other southern pines. The two slash pine varieties, the
slower-growing south Florida variety (var. densa) and the more commercial "typical" variety
(var. elliottii), were not separated in the cluster analysis of allozymes. Variation was
continuous from south to north in Florida in slash pine, with no distinct transition between the
two varieties. The monoterpene data also showed continuous variation between the two slash
pine varieties. Expected heterozygosity declined from south to north, supporting the
hypothesis that slash pine resided in a Pleistocene refugium in south Florida or the Caribbean,
migrating northward at the close of the ice age. Allozyme frequencies as well as monoterpene
compositions of slash pine and its AUSTRALES relatives showed a very close relationship
between slash pine and Bahamian Caribbean pine (P. caribaea Morelet var bahamensis).
HYBRIDIZATION AND GENE FLOW BETWEEN Pinus caribaea AND P. oocarpa.
Robert D. Westfall and Paul Hodgskiss
Institute of Forest Genetics, PSW Research Station, USDA Forest Service, PO Box 245,
Berkeley, CA 94701
Abstract: Although hybrization between Pinus caribaea and P. oocarpa is well established
in the literature, the extent of gene flow between the species in the wild is not. We present
evidence that hybridization events and introgression is highly restricted. Twenty-three
seedlots, which included 7 populations of Pinus caribaea and 8 of P. oocarpa, were
assayed for 10 allozyme loci. Differentiation between the species was low: allelic
frequencies differed by less than 0.5; Fst = 0.12 between species. In contrast, multilocus
differences by canonical analysis were high: 95% of individual genotypes could be
correctly classified to species. Using the canonical model we developed a Baysian
estimator of admixture, m, which could be applied to individual genotypes. This estimator
of pollen and megagametophytic genotypes indicated that putative hybrid seedlots were
largely simple mixtures of the two species. In tests of Fis in seedlots, only a putative hybrid
lot was statistically significant, again indicating a simple mixture. Linkage disequilibria
were generally significant in seedlots at the zone of contact between species, though the
trend was not strong. A plot of m by elevation indicated a steep stepped cline. An analysis
of this stepped cline indicated a cline width of 150 m, an effective gene flow rate of 20
m/generation0.5, and a barrier to gene flow of about 1.5 km. These data indicate that
introgression would be complete in about 5600 generations. The palynological record for
the region, though scant, suggests that the two species have been in contact, episodically, at
least, over the past 200,00 years, thus explaining the single-locus similarity between
species.
GENETIC VARIATION IN THE PERFORMANCE POTENTIAL OF INTERIOR
SPRUCE SOMATIC SEEDLINGS. Steven C. Grossnickle and Raymund Folk
(sgrossnickle@cellfor.com)
CELLFOR Inc., 3650 Wesbrook Mall, Vancouver, B.C., Canada, V6S 2L2
Abstract: Somatic embryogenesis is a tissue culture method of asexual propagation used in
forestry as a means of rapidly multiplying elite genotypes. This vegetative propagation
approach has been developed to the point where crops (i.e., ranging from 50,000 to
1,000,000) of conifer seedlings are now produced through an operational production
program. Stock quality assessment conducted on the original production scale-up efforts of
the early 1990s indicated that interior spruce (Picea glauca (Moench) Voss x Picea
engelmannii Parry ex. Engelm.) somatic seedlings were smaller and had variable
performance in comparison to zygotic seedlings (Grossnickle and Major, 1994, Can. J. For.
Res. 24:1385-1396). This presentation revisits the issue of somatic versus zygotic seedling
performance. In addition, this presentation reviews the variation in performance attributes
observed among genotypes. Somatic seedlings were produced as an operational unit with
an effective population size that met BC Ministry of Forests deployment guidelines (i.e., 34
genotypes from 12 families). A genetically improved seedlot from the same central region
of British Columbia where seedlings were planted was used to produce zygotic seedlings
for comparison purposes. Both somatic and zygotic seedlings were grown under a standard
container nursery cultural regime. A performance potential testing approach assessed the
morphological and physiological characteristics of somatic and zygotic interior spruce
seedlings (Grossnickle et al., 1991, New For. 5:77-91; Folk and Grossnickle, 1997, New.
For. 13:121-138). Somatic and zygotic seedlings met BC Ministry of Forests morphological
specifications (i.e., height and diameter) required for seedling size. Shoot growth capacity
was comparable for zygotic and somatic seedlings under optimum edaphic conditions.
Under certain limiting edaphic conditions, zygotic had greater shoot growth capacity than
somatic seedlings (i.e., low nutrients and low temperature), while in other conditions (after
drought) shoot growth was comparable. Root growth capacity was higher in somatic
seedlings under all tested edaphic conditions. Photosynthetic capability was comparable for
zygotic and somatic seedlings under optimum edaphic conditions. Freezing tolerance
declined at a comparable rate for zygotic and somatic seedlings during the shoot elongation
phase. Drought tolerance was higher in somatic seedlings under dormant conditions.
Drought tolerance declined during shoot elongation with comparable levels for zygotic and
somatic seedlings. Results indicate that somatic and zygotic seedlings have comparable
morphological development and physiological performance under a range of assessment
conditions. Genotypic variation was evident in all performance potential testing conditions,
with some genotypes performing better and others worse than the zygotic seedlot. The need
for improved understanding of ecosystem processes and related carbon dynamics in
response to changes in global climate has led to the construction of several dynamic global
vegetation models (DGVM). Simulations performed with such models have generally been
successful in approximating the distributions and magnitudes of key ecosystem indicators
at the global scale. However, detailed validations against observations made in different
ecosystems at smaller spatio-temporal scales are still highly desirable. The objectives of
this paper address some of these validation requirements. First, we present and discuss
results of site-based simulations of energy, water and carbon fluxes for different forest
stands in central Canada, using the Integrated BIosphere Simulator (IBIS) of Foley et al (a
DGVM). Agreements between observed and simulated energy balances and CO2 fluxes
were generally very good. In a second validation exercise, the results of a national scale
simulation of Canada’s forests were compared with a recently compiled gridded dataset of
forest biomass derived from the CFS Canadian Forest Inventory (CanFI) database. Plant
functional types (PFT) used in IBIS were parameterized to more closely represent the
characteristics of Canada’s forest vegetation. Simulated vegetation distribution and biomass
densities were found to agree with the gridded dataset better than were obtained using the
global PFT parameterization.
LANDSCAPE GENETIC STRUCTURE OF Pinus banksiana: ALLOZYME
VARIATION. Cuauhtemoc Saenz-Romero1, Raymond P. Guries2, Andrew I. Monk2
(csaenz@zeus.ccu.umich.mx), (rpguries@facstaff.wisc.edu), (aimonk@facstaff.wisc.edu)
1
Universidad Michoacana de San Nicolás de Hidalgo, Instituto de Investigaciones sobre los
Recursos Naturales, Apartado Postal 2-105, 58041 Morelia Michoacán, México
2
Department of Forest Ecology and Management, University of Wisconsin-Madison, 1630
Linden Drive, Madison WI 53706, U.S.A.
Abstract: The extent and patterning of genetic diversity at a landscape scale (30 km x 30
km) was investigated in 82 natural Pinus banksiana (jack pine) stands in Wisconsin using
fourteen polymorphic allozymes. Many of today’s jack pine forests originated following
fire or agricultural abandonment creating a forest mosaic fragmented by past land use. Most
measures of genetic diversity and overall allelic frequencies varied little among these
stands, and genetic distances were small (averaging 0.008). Genetic differentiation amongstands is limited but significant (FST = 0.022) with stands formerly in agricultural use
characterized by lower levels of differentiation. Autocorrelation analysis provides evidence
for subtle population genetic structuring at a scale of 8 to 15 km. We recommend that
public and industrial land managers maintain some naturally-regenerated jack pine stands at
a landscape scale corresponding to major soils units as a genetic conservation measure.
A CASE STUDY OF A PROVENANCE TEST USING TREND ANALYSIS WITH
CORRELATED ERRORS AND SAS PROC MIXED. Cuauhtemoc Saenz-Romero1,
Erik V. Nordheim2, Raymond P. Guries2 and Peter M. Crump3
(csaenz@zeus.ccu.umich.mx), (nordheim@facstaff.wisc.edu), (rpguries@facstaff.wisc.edu)
and (pmcrump@facstaff.wisc.edu)
1
Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San
Nicolás de Hidalgo. Apdo. Postal 2-105, 58041 Morelia Michoacán., México 2Department
of Forest Ecology and Management, University of Wisconsin - Madison, 120 Russell labs,
1630 Linden Drive, Madison WI 53706, U.S.A. 3Department of Computing and Biometry,
College of Agriculture and Life Sciences, University of Wisconsin - Madison, 1675
Observatory Drive, Madison WI 53706, U.S.A.
Abstract: A case study of a provenance test using trend analysis with correlated errors and
SAS PROC MIXED. Cuauhtemoc Saenz-Romero, Erik V. Nordheim, Raymond P. Guries
and Peter M. Crump. Can. J. For. Res. A statistical analysis was performed on data from a
provenance test of Pinus banksiana Lamb. 1.5 year-old open-pollinated seedlings from 47
stands collected in five distinct soil-moisture classes within a pine-barren landscape, in
west-central Wisconsin. A large-scale environmental gradient across the nursery bed and
small-scale among-microsite variability were evident in seedling responses. We compared
three analyses in terms of their capabilities for accounting for such within-experimental
area variation: (A) a “standard analysis” using ANOVA for a randomized complete block
design, (B) trend analysis in addition to (A), and (C) correlated errors in addition to (B).
PROC GLM of the Statistical Analysis System (SAS) was used for analyses (A) and (B);
PROC MIXED was necessary for analysis (C). We concluded that analysis (C) was the best
option for adequately modeling the data, reducing the error variance and consequently,
detecting significant differences among sets of stands grouped by soil-moisture classes. We
suggest that the row and column position of each experimental unit in provenance or
progeny tests with forest species be recorded in order to allow for the possibility of
conducting analysis of this type. As an important caveat, we found an unexpected bimodal
likelihood surface when PROC MIXED included a term for correlation among plots; this
requires use of the PARMS statement when applying PROC MIXED.
FIELD RESULTS OF WHITE PINE BLISTER RUST RESISTANCE IN SUGAR
PINES AND WESTERN WHITE PINE SEEDLINGS. Andrew D. Bower and
Richard A. Sniezko
(abower@fs.fed.us) and (rsniezko@fs.fed.us)
PRESENTATION PROVIDED
USDA Forest Service, Dorena Tree Improvement Center, 34963 Shoreview Road, Cottage
Grove, Oregon 97424, USA
Abstract: Seedlings from 12 sugar pine (Pinus lambertiana) and 13 western white pine
(Pinus monticola) families were planted at Happy Camp, California in 1996, for field
validation of families artificially screened for white pine blister rust (Cronartium ribicola).
1-0 container stock from a mixture of resistant and non-resistant families was planted in 12
blocks in a randomized complete block design. An initial assessment was done in early
summer 1999, in which height, number and type of cankers (normal, bark reaction, partial
bark reaction or blight) was recorded. These results indicated moderate levels of blister rust
infection, with sugar pine found to have a significantly higher percentage of trees infected
(both active and inactive cankers) and significantly more stem infections per infected tree
than western white pine (based on all trees, including healthy). Height differed significantly
between species, and among families within a species, but the number of cankers per tree
was not significantly different between families at this age. An unexpected result from this
assessment is the very high percentage of infections that are bark reactions (completely
inactivated infections), despite the fact that only some of the families of both species were
selected this mechanism. In addition, the results indicated that there was an association
between species and canker type for normal, bark reaction and partial bark reaction type
cankers, with SP having a greater number of bark reactions than expected, and WWP
having a greater number of normal and partial bark reactions than expected. The reason for
this high level of bark reaction is unknown at this time. A subsequent assessment is
scheduled for summer/fall 2000 to track the progression of blister rust infection in the
individual families, and contrast differences in infection, and subsequent mortality between
the two species. In addition, it will show whether the observed bark reactions have
remained inactive, and the current status of infection scored in 1999 as partial bark reaction.
LANDSCAPE GENETIC STRUCTURE OF Pinus banksiana: SEEDLING TRAITS.
Cuauhtemoc Saenz-Romero1 and Raymond P. Guries2
(csaenz@zeus.ccu.umich.mx) and (rpguries@facstaff.wisc.edu)
1
Universidad Michoacana de San Nicolás de Hidalgo, Instituto de Investigaciones sobre los
Recursos Naturales, Apartado Postal 2-105, 58041 Morelia Michoacán, México
2
Department of Forest Ecology and Management, University of Wisconsin-Madison, 1630
Linden Drive, Madison WI 53706, U.S.A.
Abstract: The extent and patterning of genetic diversity at a landscape scale (30 km x 30
km) was investigated using seedlings from 47 stands of Pinus banksiana Lamb, collected in
Jackson County, Wisconsin, USA. Seedlings grown for six months in a greenhouse were
evaluated for the number of cotyledons, the length of the longest cotyledon, the number of
early needle fascicles, seedling height, timing of bud set, and the dry weight of roots,
foliage, stem and total seedling, shoot:root ratio and foliage:root ratio. A pronounced
genetic structure exists for most traits, with stands showing significant differentiation at
geographic distances up to 25 km. Seedlings originating from trees growing on sandy sites
were larger than those from sandy-loam sites. The scale and pattern of differentiation for
several traits parallels the scale and pattern of soil variation on the landscape, supporting
the hypothesis that stand genetic differentiation corresponds to a gradient of environmental
differences. The results could be useful in a program of genetic resource management.
EL MEJORAMIENTO GENÉTICO FORESTAL Y SU APLICACIÓN EN MÉXICO.
Lilia del C. Mendizábal Hdez, Juan Alba Landa y Armando Aparicio Rentería.
Instituto de Genética Forestal, Universidad Veracruzana, Xalapa, Ver. A.P. 551 E-mail:
genfor@dino.coacade.uv.mx
Resumen: Con el propósito de tener un registro del origen geográfico de la semilla
recolectada de las diversas especies forestales utilizadas en los programas de reforestación,
el Dr. Thompson Conkle ha identificado diferentes zonas de semillas en México, de
acuerdo a los lineamientos utilizados por el Servicio Forestal del departamento de
Agricultura de los Estados Unidos (USDA Forest Service), en los cuales se considera de
particular importancia que la semilla debe ser recolectada dentro de los 160 Km al sur o
norte del sitio de plantación y diferir en la elevación del sitio en menos de 365 m cuya
intención es reducir los riesgos de fracaso mediante el establecimiento de material genético
adaptado localmente. Sin embargo, es importante mencionar que no se puede hacer una
zonificación real sin el establecimiento previo de ensayos de especies y procedencias por lo
cual en México, y particularmente en el estado de Veracruz, a través del programa de
“Mejoramiento Genético Forestal” se han establecido ensayos de procedencias/progenie, de
progenie y de especies que abarcan las siguientes: Pinus caribaea con 5 procedencias de
Honduras; Pinus oocarpa con 3 procedencias de Guatemala y 1 de México; Pinus
maximinoi con 5 procedencias de México y 3 de Honduras, Pinus greggii con 3
procedencias de México; Liquidambar styraciflua con 5 procedencias de México, 4 de
Honduras, una de Guatemala y una de Nicaragua; Pinus patula con progenie procedente de
huertos semilleros de primera y segunda generación de selección; y en cuanto al ensayo de
especies se tiene el de Pinus cembroides subsp. orizabensis y Pinus. En total se tiene bajo
prueba 30 procedencias y 259 familias. Dichos ensayos se han establecido abarcando un
rango que va de los 210 hasta los 2720 msnm. Con los resultados de estas pruebas,
podemos determinar las mejores fuentes parentales de reproducción de cada especie en el
área de influencia altitudinal y longitudinal de su establecimiento para una estrategia de
multiplicación sexual y asexual según sea el caso y la pertinencia, a partir de las cuales se
puede iniciar un proceso que permita dar certidumbre al establecimiento de plantaciones
comerciales con altos rendimientos según la evaluación de la pruebas antes citadas así
como el establecimiento y manejo de bancos clonales como fuente de generación y
aplicación del conocimiento, y de esta manera, fortalecer la cultura silvícola que se merece
el país como depositario de casí 3000 especies de árboles componentes de su flora.
POLIMORFISMO BIOQUÍMICO EN SEMILLAS DE GENOTIPOS ELITES DE
Pinus greggii Engelm, EN VERACRUZ, MÉXICO. Lourdes G. Iglesias, Sergio L.
Corro y Armando Aparicio
Instituto de Genética Forestal,
georg@dino.coacade.uv.mx
Universidad
Veracruzana.
A.P.
551.
email:
RESUMEN: Se realizó en el Instituto de Genética Forestal de la Universidad Veracruzana
un estudio del polimorfismo bioquímico presente en muestras de semillas de árboles
seleccionados fenotípicamente para las características: rectitud del fuste, poda natural y
calidad de la copa en P. greggii Engelm, provenientes de un rodal natural situado en la
localidad de “Carrizal Chiquito”, municipio de Zacualpan,Ver., México, situada en un
rango altitudinal de 1,600 a 1,250 msnm con el fin describir y analizar la variación
bioquímica presente en dicha población. Se utilizó la técnica de SDS-PAGE y PAGE en
sistemas discontínuos de láminas verticales de geles de poliacrilamida (8.5-5%) para el
estudio de la variación en la composición de proteínas totales e isoenzimas Esterasas y
Fosfatasas Ácidas de cada genotipo en estudio. Las variantes polimórficas detectadas
fueron previamente codificados con valores 0 y 1 antes de ser procesados por Análisis
Factorial de Correspondencias Simples. Los resultados obtenidos revelaron la presencia de
9 bandas distintiva de proteínas totales bien delimitadas en dos regiones electroforéticas:
PT1 y PT2. Un marcado polimorfismo fue observado asimismo en la composición de
isoenzimas Esterasas (6 bandas polimórficas) lo que contrastó con el menor polimorfismo
observado en la composición de isoenzimas Fosfatasas Acidas (1 banda polimórfica).Los
resultados del Análisis Factorial de correspondencias permitió agrupar los genotipos y las
variantes polimórficas detectadas. Se discuten los resultados obtenidos en función de la
posición del rodal natural como el extremo más sur del rango de distribución natural de la
especie y su posible implicación por la alta capacidad de esta especie para formar híbridos
con la especie de Pinus patula dominante en la mencionada región. Por todo ello esta
población tiene potencial de producción de progenies altamente variables que pueden ser
vocacionadas a través de sus paquetes de variación en distintos tipos de ambientes a fin de
conciliar la erosión genética de las especies con la erosión de los sitios naturales. Con ello
se brindaría una respuesta científico técnica al alto grado de erosión de los suelos que se
presenta en las distintas latitudes y altitudes del mundo.
FOREST TREE PHYSIOLOGY
FISIOLOGÍA DE ÁRBOLES FORESTALES
INTERSPECIFIC DIFFERENCES IN RATES OF BASE CATION
IMMOBILIZATION IN THE STEM OF SOME HARDWOODS OF EASTERN
CANADA ARE LARGELY AGE- OR SIZE- DEPENDENT. Patricia Boucher and
Benoît Côté
(coteb@nrs.mcgill.ca)
PRESENTATION PROVIDED
Department of Natural Resource Sciences, Macdonald Campus of McGill University,
21,111 Lakeshore, Sainte-Anne-de-Bellevue, QC, Canada, H9X 3V9
Abstract: Large amounts of nutrients are immobilized in woody tissues as forests proceed
towards late successional stages. The objective of this study was to compare concentrations,
contents and rates of base cation immobilization of the stem of some common hardwoods
of eastern Canada (sugar and red maple, beech, basswood, white ash and red oak. The study
site was located on the island of Montreal in southern Quebec (45o25’N, 73o57’W, 30 m
above sea level). Nineteen trees ranging from 20 to 40 cm in diameter were harvested. Stem
volume, wood density, stem tissue concentrations in K, Ca and Mg, and the area covered by
the projection of the tree crown on the ground were measured. Tree nutrient contents were
determined and allometric equations between tree nutrient content and DBH were
established. Between 20 and 25 trees per species were sampled for age and diameter.
Except for the low Mg concentration in red oak, interspecific differences in tissue
concentrations were generally small. White ash for K, sugar maple for Ca, and sugar maple
and beech for Mg were highest in content in the 40-cm diameter class. Stem Mg content
was lowest in red oak across diameter classes. Highest rates of immobilization for white
ash and basswood were measured in young trees whereas sugar maple generally had among
the fastest rates of immobilization when trees were both the largest and the oldest. Our
study suggests that tree species growing in mixed stands are likely to develop different
patterns of base cation immobilization over time that may contribute to an efficient
utilization of site nutrients throughout stand development.
USE OF GROUND PENETRATING RADAR TO STUDY TREE ROOTS IN THE
SOUTHEASTERN UNITED STATES. J.R. Butnor1, J.A. Doolittle2, L. Kress1, S.
Cohen1, D. Delea3, and K.H. Johnsen1
(jbutnor@fs.fed.us)
1
Southern Research Station, USDA Forest Service, 3041 Cornwallis Road, Research
Triangle Park, NC 27709, USA 2 USDA-NRCS, 11 Campus Boulevard, Suite 11 Newtown
Square, PA 19073, USA 3 Geophysical Survey Systems, 13 Klein Drive, North Salem, NH
03073, USA
Abstract: Tree roots have been observed by technicians using ground-penetrating radar
(GPR) to image sub-surface geophysical features or artifacts. For some time, roots were
considered unwanted noise and were not the focus of GPR studies. Recently GPR was used
to map coarse roots (>3 cm) of a 50-year old Quercus petraea using non-invasive means
(Hruska et al 1999). The objectives of this study are to expand on the work of Hruska et al
(1999) and assess the feasibility of using GPR for similar work in the southeastern United
States. The radar unit used in this study was the Subsurface Interface Radar System (SIR)
2000 with 1.5 gHz and 400 mHz antennae. Study sites were selected in the Southern
Piedmont, Carolina Sandhills, and Atlantic Coast Flatwoods to assess the feasibility of
GPR over a broad range of soil conditions. Studies commenced to determine the best
antennae, ability to resolve roots and buried organic debris, assess root size and gauge the
practicality of using GPR at each site. In the Carolina Sandhills, (16) 1 x 1 meter plots were
scanned with the 1.5 gHz antennae using overlapping grids. The plots were later excavated,
large roots mapped, and all roots classified by size and oven dried. Roots as small as 0.5 cm
were detected with GPR. Sandy soils gave the best resolution, while high moisture and high
clay content seriously degraded resolution and observation depth. We were able to size
roots (0.5 to 5 cm) that were oriented perpendicular to the radar sweep (r2 = 0.89 P
=0.0001). Preliminary work using image analysis software to relate size/magnitude of radar
parabolas to actual root biomass has been less promising (r2 = 0.43 P = 0.0998). Orientation
and geometry of the reflective surface seems to have greater influence on parabola
dimensions than root size.
DEPTH OF SENSOR PLACEMENT AND TREE SIZE AFFECT SAP FLUX DENSITY
MEASUREMENTS OF LOBLOLLY PINE. Shufang Yu1, Jim L. Chambers1, Guddanti
Suresh1, Zhenmin Tang1, P. Joy Young1, Mary Anne Sword2, and James P. Barnett2
(syu1@lsu.edu)
1
School of Forestry, Wildlife, and Fisheries, Louisiana Agricultural Experimental Station,
Louisiana State University Agricultural Center, Baton Rouge, LA 70803, USA 2 USDA
Forest Service, Southern Research Station, Pineville, LA 71360, USA
Abstract: To correctly estimate canopy transpiration using (as production of) sap flux
density (SFD) and sapwood area, the variation of SFD at different radial positions and in
different sizes of trees were examined with constant heat sensors. The study was conducted
in an 18-year-old loblolly pine stand located on the Kisatchie National Forest in Central
Louisiana. Ten trees that ranged in stem diameter from 12 to 30 cm were chosen for
measuring SFD. Heated and unheated thermocouple pairs were inserted at 3 to 7 radial
depths within each tree from the outer to inner sapwood. The heated sensor was heated at
the inner most 2 cm of its depth (0-2, 2-4, 4-6, 6-8, 8-10, 10-12, and 12-14 cm) according
to the diameter of each sample tree. Data was automatically scanned every 30 minutes. At
the maximum flux, we observed that SFD was significantly different among radial
positions and among tree sizes during the midday (11:00-14:00). Trees of the maximum
size studied had the greatest radial difference in SFD. SFD's at the 0-2cm depth and 2-4cm
depth were significantly higher than other radial positions. SFD was reduced from 45% to
72% from the 2-4, to the 12-14 cm depth, compared to SFD at the 0-2cm depth. Medium
and small trees studied showed only a significant SFD change in the outer most sapwood
compared to other radial positions. Reductions in SFD with depth were great in larger trees.
To model tree water loss, total tree SFD measurements must account for changes in radial
SFD and tree sizes.
INFLUENCE OF INTENSIVE MANAGEMENT ON CANOPY TRANSPIRATION
IN LOBLOLLY PINE. Thomas Stokes1, Lisa Samuelson1, Greg Somers1 and Tom
Cooksey2
(stoketa@forestry.auburn.edu), (samuelson@forestry.auburn.edu),
(somers@forestry.auburn.edu) and (tom.cooksey@ipaper.com)
PRESENTATION PROVIDED
1
School of Forestry & Wildlife Sciences, Auburn University, AL 36849-5418, USA
International Paper, Southlands Experiment Forest, 719 Southlands Road, Bainbridge, GA
31717, USA
2
Abstract: Because of the predicted increase in consumption of pulpwood and other wood
resources over the next half century, forest sustainability has become a great concern to
most ecologists and forest industries today. Many suggest that this demand can be met by
planting trees on small intensively managed plantations. To better understand the potential
of intensive management in maximizing productivity, we examined the influence of (i)
complete weed control,(ii) weed control and irrigation, and (iii) weed control and irrigation
with a fertilizer solution (fertigation) on diurnal and seasonal variation in leaf and canopy
physiology of 5-yr-old loblolly pine (Pinus taeda L). Diurnal patterns of stomatal
conductance (gs) and leaf water potential (L) were measured four times during the 1999
growing season. Hourly measurements of photosynthetically active radiation, air
temperature, vapor pressure deficit, sap flow (l hr-1) and whole tree transpiration rate (E)
were monitored for one year. Sap flow or E at maximum gs, after which gs exhibited a
diurnal decline, did not differ with treatment. Treatment did not influence E crit, defined as E
corresponding to the L at which the slope of the relationship between L and E deviated
from linear, and average Ecrit was 1.2 mmol m-2 s-1. In contrast, L at Ecrit was lower in the
control treatment (-1.61 versus –1.28 and –1.21 MPa in the control, irrigation and
fertigation treatments, respectively). Although total water loss was higher in trees
supplemented with nutrients and water, maximum E relative to canopy leaf area was similar
between treatments. We conclude that the critical minimum leaf water potential was
increased by irrigation, but the maximum rate of E, after which stomata limit water loss to
avoid cavitation, in 5 yr-old loblolly pine was unaffected by nutrient and water availability.
EFFECTS OF JIFFY FORESTRY PEAT PELLETS ON ROOTING AND
SUBSEQUENT FIELD PERFORMANCE OF STEM CUTTINGS OF LOBLOLLY
PINE. Anthony V. LeBude, Frank A. Blazich and Barry Goldfarb
Dept. of Forestry, NCSU Loblolly and Slash Pine Rooted Cutting Program, North Carolina
State University, Raleigh, NC 27695-8002
Abstract: Experiments conducted in January (hardwood cuttings) and June (softwood
cuttings) 1998 compared rooting and root dry weight (DW) of stem cuttings of three fullsib families of loblolly pine (Pinus taeda L.) rooted in Jiffy forestry peat pellets and Ray
Leach Super Cells. Ray Leach Super Cells (vol.=162 cm3) served as the control and
contained a medium of 2 peat : 3 perlite (v/v). Pellet sizes used were 25-65, 30-65, 36-65,
36-75, 42-65, 42-80, and 50-95 (dry diam.– expanded height in mm). Cuttings were taken
from hedged stock plants and rooted for 12 weeks under mist in a humidity-controlled
greenhouse. Following evaluation for rooting in the June experiment, approximately 500
rooted cuttings in pellets and Ray Leach Super Cells were field planted in eastern Georgia
in December 1998 to study the effect of pellet size and cutting development on first-year
field growth. Rooting percentages in January for hardwood cuttings rooted in pellet sizes
42-80 (36%) and 50-95 (57%) were less than the control (83%). Root DW for each pellet
size was less than the control. Rooting percentage in June for softwood cuttings rooted in
pellet size 36-65 (77%) was greater than the control (64%) whereas rooting percentages for
cuttings rooted in pellet sizes 42-80 (50%) and 50-95 (52%) were less than the control.
Root DWs for cuttings in pellet sizes 25-65, 30-65, 36-65, and 42-65 were less than the
control. Field performance data will be presented.
RELATIONSHIP BETWEEN HYDRAULIC PATHWAY LENGTH AND FOLIAR
13C IN LONGLEAF PINE. Price C. McLemore, III, Lisa J. Samuelson, Greg L.
Somers
(mclempc@auburn.edu), (samuelson@forestry.auburn.edu), (somers@forestry.auburn.edu)
PRESENTATION PROVIDED
Auburn University, 108 M. White Smith Hall, Auburn, Al 36849
Abstract: Reductions in ANPP due to age/size effects, and the mechanisms controlling
forest productivity are of interest to foresters, scientists, and industrialists. Increased
knowledge of the mechanisms contributing to age/size related changes in productivity will
improve forestland management practices and define the relationship between form and
function. The goal of this project was to increase understanding of age/size related changes
in productivity by examining branch morphology and leaf physiology of different size
Pinus palustris. We tested the hypothesis that increasing length of the hydraulic pathway
results in increased hydraulic resistance and decreased leaf carbon gain. We used 13C as an
integrative temporal measure of stomatal conductance and photosynthetic activity. Total
hydraulic pathway lengths (THPL - xylem length from the stump to each individual tuft)
ranged from 3.8-21.8 m and tree diameters measured 3.5-30 cm. Twenty-two to 65 tufts
were sampled per large/old tree (THPL 14-22 m) and a total of 28 tufts were pooled from
small/young trees (THPL 3.5-9 m). A curvilinear model with log transformed THPL,
grouping by size class (large/old and small/young trees), and individual tree intercept terms
explained 81% of the variation in 13C. Foliage 13C for large trees ranged from -25.4 to 28.6o/oo and -26.4 to -29.7 o/oo for the smaller trees and 13C increased with increasing
THPL for both size classes. A significant relationship between nitrogen and branch length
was not detected, which indicated that differences in 13C between tufts were not
confounded by microclimate. Although cause and effect were not tested, correlation
between 13C and the length of the hydraulic pathway indicated that hydraulic limitation is
important in understanding age/size related change in productivity of longleaf pine.
BREEDING FOR STRESS TOLERANCE
CRUZAMIENTOS PARA TOLERANCIA AL ESTRÉS
GENETIC VARIATION IN DROUGHT HARDINESS OF COASTAL DOUGLASFIR SEEDLINGS. T.S. Anekonda, M.C. Lomas, and W.T. Adams
Department of Forest Science, 321 Richardson Hall, Oregon State University
Corvallis, OR 97331, USA
Abstract: Genetics of drought hardiness traits and their interrelationships were investigated in
39 full-sib families of coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.)
Franco) seedlings grown in raised nursery beds. The experimental design was a split plot
replicated in five blocks. Main plots consisted of control (well-watered) and drought
treatments applied in the second and third growing seasons, with families in 4-tree row subplots. Drought hardiness traits were percent shoot damage and percent xylem cavitation (nonfunctioning tracheids in each annual growth ring as detected by safranin dye perfusion)
measured at the end of each growing season, and 3rd-year diameter increment and hydraulic
conductivity (the quantity of water transported through a given length of stem under a constant
pressure) at the end of third season. Height and diameter in the control treatment were used to
assess growth potential in the absence of drought. Mean shoot damage in the third season
(32%; severe drought) was twice that in second season, when only a moderate drought was
applied. Families differed significantly in nearly all hardiness traits, although the genetic
determination (family variance / phenotypic variance) for hardiness traits was about one-half
as great as for growth potential traits. Genetic correlations between drought hardiness traits in
the same year were high (average rg =|0.97|), and were moderate between the traits measured
in different years (average rg = |0.49|), despite the large difference in severity of the drought.
Growth potential was essentially uncorrelated with drought hardiness (average rg=0.06 in year
2 and -0.13 in year 3) in both growing seasons. Much potential exists for identifying droughthardy families at seedling stage and using this information for deployment or breeding
purposes. In addition, drought hardiness at the seedling stage does not appear to be related to
inherent growth potential under favorable moisture regimes.
GROWTH EFFICIENCIES OF DIVERSE Pinus taeda FAMILIES AS AFFECTED
BY GENETICS OF THE ROOT SYSTEM. James E. Grissom and Steven E.
McKeand
(jegriss2@unity.ncsu.edu)
PRESENTATION PROVIDED
Department of Forestry, North Carolina State University, Campus Box 8002, Raleigh, NC,
27695
Abstract: Production of stemwood depends on photoassimilation in leaves, which in turn
depends on resource supply from roots. The rate at which stemwood is produced relative to
leaf area is important since it expresses the efficiency of stem production. An important
question thus becomes: What factors inside the tree influence the functioning of the
photosynthetic leaf area? Since such factors may originate from the roots as well as within
the leaves, our approach seeks to alleviate the confounding effects of root and shoot
processes. The main objectives are to: 1) evaluate genetic effects of roots on processes
conducted in the leaves, such as CO2 fixation and carbon allocation, and 2) determine
whether root systems, by physiologically affecting leaf functions, can substantially impact
growth efficiency. We used a novel grafting method with loblolly pine seedlings from
diverse provenances to evaluate rootstock effects on stem growth efficiency. Seedlings of
fast- and slow-growing families were grafted at 12 weeks of age in all possible
combinations, and planted on an infertile site in a split-plot layout with half of the plots
fertilized periodically. Tree height, volume, and biomass accumulation were measured over
two growing seasons. Rootstock effects on stem growth efficiency were detected in the
fertilized treatment. Rootstocks of selected families were associated with changes in
photosynthetic gas exchange in leaves of other selected families. It is proposed that, in
these families, differences in growth efficiency are partly caused by differences in genetic
properties of root systems.
NORMS OF REACTION OF STABLE AND UNSTABLE DOUGLAS-FIR
GENOTYPES ACROSS TEMPERATURE AND MOISTURE REGIMES:
IMPLICATIONS FOR BREEDING AND CLIMATE CHANGE. Sally N. Aitken and
Tongli Wang
(aitken@interchg.ubc.ca)
PRESENTATION PROVIDED
Department of Forest Sciences, University of British Columbia, 3041-2424 Main Mall,
Vancouver, British Columbia, Canada V6T 1Z4
Abstract: This project was undertaken to determine: 1) if genotype-by-environment
interaction (g x e) observed across coastal Douglas-fir field progeny test sites could be
reproduced using experimental seedling test environments; 2) if families that are ‘stable’
and ‘unstable’ in the field can be correctly identified in seedling experiments; and 3) what
the relative roles of soil moisture and temperature are in inducing g x e. On the basis of 12year stem volume of the progeny of 372 parents crossed in 62 six parent half-diallels and
planted on 12 field test sites in British Columbia, pairs of coastal Douglas-fir parents were
selected with similar breeding values but contrasting stabilities based on relative
contributions to family-by-site variance. Seedlings from two or three full-sib families of
each of the 16 parents (45 families total) were grown in outdoor, raised nursery beds under
four treatments: 1) ambient soil temperature, well-watered; 2) ambient soil temperature,
moderate drought (predawn xylem water potential -1.2 mPa); 3) warm soil (ambient + 3 to
4oC), well-watered; and 4) warm soil, moderate drought. The norms of reaction for growth
(total amount and rate of height growth, and total diameter growth) of stable and unstable
families varied significantly (p<0.01) among the four treatments. The average response to
increased soil temperature was positive and significant (p<0.001), but stable and unstable
families differed markedly in their reaction to temperature (stability class-by-temperature
interaction; p<0.05). Stable and unstable families responded similarly to soil moisture, with
significant reductions in growth due to drought (p<0.001); but there was no stability classby-moisture interaction. Norms of reaction of stable and unstable families did not differ for
timing of bud set or fall cold hardiness. We conclude that changes in temperature may
produce greater g x e in the performance of select Douglas-fir genotypes than changes in
moisture, and that selecting and deploying genotypes with a mixture of norms of reaction
for temperature may be an appropriate strategy for addressing future climatic uncertainty.
TROPICAL SILVICULTURE
SILVICULTURA TROPICAL
REGENERATION OPTIONS FOR RAPID ESTABLISHMENT OF Pinus greggii
SEEDLINGS. Arnulfo Aldrete1 and John G. Mexal2
New Mexico State University, Agronomy and Horticulture Dept., Box 30003, Dept.
3Q, Gerald Thomas 254, Las Cruces, NM, USA
Abstract: One of the most important problems for reforestation programs in Mexico is the
low seedling survival after outplanting. Factors directly involved with this problem include
the group of cultural practices applied to the seedlings during the nursery production
process. Two experiments, a greenhouse and an outplanting trial, were carried out at Fabian
Garcia Science Center at New Mexico State University. The objective of this research was
to compare the effect of different cultural practices in nursery growth and outplanting
performance of Pinus greggii seedlings grown under the traditional polybag production
system used in Mexico and an alternative containerized production system. The cultural
practices evaluated in this research were chemical root pruning, sources of fertilization, top
pruning, and container size. The results from the application of these practices in the
nursery indicated that chemical root pruning improves most morphological characteristics
of Pinus greggii seedlings. The major impact of this practice was reflected in the root
system because seedlings had increased root:shoot balance and more fibrous root systems.
In addition, chemical root pruning either eliminates or significantly decreases root spiraling
and root egression from polybags. Fertilization was necessary to produce high quality
seedlings, however, there was no significant differences between the soluble fertilizer
applied through the irrigation system and the slow release fertilizer applied to the media at
sowing time. Top pruning was effective in controlling height of seedlings but also
decreased the final root collar diameter. Finally, container size significantly affected some
of the morphological characteristics of the seedlings. In general, the greater the container,
the larger the seedling within the five different container sizes evaluated. The outplanting
trial showed that seedlings that were chemically pruned had better growth increments after
eight months in the field. Top pruned seedlings completely recovered by the end of the
experiment and were growing as fast as non-pruned seedlings. Seedlings produced in
polybags had significantly higher survival than seedlings produced in styroblocks after
eight months in the field. Regarding container size, seedlings produced in larger container
performed better than those produced in smaller containers. Results from this research
indicated that chemical root pruning is a simple cultural practice that can be applied in the
nurseries to improve the quality of the seedlings and eliminate the problems traditionally
associated with the polybag nursery production system. In addition, seedlings with a better
root system will have a better opportunity to survive after outplanting resulting in great
benefits for reforestation programs.
ASPECTOS ECOLOGICOS Y DE DENSIDAD DE LA REGENERACION DE Picea
EN NUEVO LEON, MÉXICO. Salvador Valencia-Manzo1, Celestino Flores-López,
Sergio Braham-Sabag, Miguel A. Capó-Arteaga
(savalencia@narro.uaaan.mx)
1
Profesor e Investigador. Universidad Autónoma Agraria Antonio Narro. Departamento
Forestal. Buenavista, Saltillo, Coah. MEXICO. C.P. 25315
RESUMEN. Se realizó un estudio del género Picea del Estado de Nuevo León, con el
objetivo de describir las condiciones de autoecología de este género. En el presente trabajo se
presentan exclusivamente los resultados de la regeneración. Se estudió el género en tres
localidades: La Marta, Rayones; La Encantada, Zaragoza; y La Trinidad, Montemorelos. En
cada localidad se establecieron dos sitios permanentes de muestreo. Se utilizaron sitios de 80
m2 para evaluar la densidad (número de individuos/ha) de todas las especies leñosas, menores
de 5 cm de diámetro normal, consideradas como regeneración. Se obtuvo la densidad a nivel
de localidad, así como densidad total y relativa por género y por categoría de altura en cada
género. Picea engelmannii var. mexicana se presenta en la localidad La Marta, en ladera alta
de montaña, con clima templado, en exposición Norte, con una fuerte pendiente. P.
martinezzii se presenta en las localidades La Encantada y La Trinidad, en la primera se
localiza en una cañada donde existe mayor húmedad y menor temperatura, la exposición es
Norte, pendiente moderada, suelo rico en materia orgánica y alto contenido de arcilla. La
localidad La Trinidad se presenta en una falla geológica de la montaña que le hace parecer
como un cañón, en donde también se favorece la mayor humedad y menor temperatura, la
exposición que predomina es zenital. La mayor densidad de regeneración (38562
individuos/ha), incluyendo todas las especies leñosas, se presentó en La Encantada. La
densidad del género Picea fue mayor en La Marta (688 individuos/ha), después en la
Encantada (500 individuos/ha); y por último en La Trinidad (188 individuos/ha). La menor
densidad de Picea en La Trinidad es probable se deba a la falta de protección en esta área, ya
que incluso se observó dañó por ramoneo del ganado.
NURSERY CULTURAL PRACTICES AFFECT EARLY SURVIVAL AND
GROWTH OF TROPICAL HARDWOODS FOLLOWING OUTPLANTING. R.A.
Cuevas Rangel, J.G. Mexal, P. Negreros Castillo and C. Parraguirre Lezama
INIFAP, Coyoacan, Mexico; New Mexico State University, Las Cruces, NM; Iowa State
University, Ames, Iowa; INIFAP, Bacalar, Quintana Roo, Mexico
Abstract: Caoba (Swietenia macrophylla) and cedro rojo (Cedrela odorata) are valuable
tropical hardwoods distributed throughout Central and Southern Mexico. About 10,000 m3
are harvested annually, which represents 70% reduction of harvested volume from fifty
years ago (Cuevas-Lopez, 1947). Poor survival of plantings carried out by communities is
one reason for reduced harvests. The objective of this study was to evaluate nursery cultural
practices and their effect on survival and growth in the field. Three different production
systems were evaluated at the INIFAP Bacalar Research Station in Quintana Roo Mexico:
1) caoba seedlings grown in polybags with soil, 2) cedro seedlings grown as bareroot
seedlings, and 3) both species grown at New Mexico State University in 164ml Ray Leach
tubes containing peat moss and vermiculite. The treatments consisted of seed orientation
(for caoba) and fertilization with urea and triple super phosphate for both species.
Randomly selected seedlings were measured for growth parameters and foliar and soil
nutrient analysis. In the nursery, polybag-grown caoba seed orientation had no significant
effect on seedling morphology. Fertilization increased growth, however there was a strong
block effect with increasing shade influencing foliage color and seedling size. For barerootgrown cedro seedlings, fertilization had no effect on seedling size but there was a strong
growing density effect confounding any response. At the outplanting site, neither
fertilization nor stocktype had a significant effect on survival of caoba, but fertilization did
increase height by 25% and diameter by 60%. Fertilization of cedro had no effect on field
survival or growth. For both species, there was a strong interaction between initial seedling
diameter and survival at 28 months, suggesting a minimum seedling diameter of 5mm at
time of outplanting for optimum survival.
PRODUCCIÓN DE SEMILLAS DEL GÉNERO PINUS EN HUERTOS Y
RODALES SEMILLEROS DE SMURFIT CARTÓN DE COLOMBIA. N. Isaza1 , W.
S. Dvorak 2 , & J. López Upton 3
(nisaza@smurfit.com.co), (dvorak@unity.ncsu.edu), (uptonj@colpos.colpos.mx)
PRESENTATION PROVIDED
1
Ingeniera de Investigación Forestal, Smurfit Cartón de Colombia, A.A. 219 Cali,
Colombia 2 Director, CAMCORE Cooperative, College of Forest Resources, North
Caroline State University, Raleigh, NC 27695 USA 3 Profesor Investigador Asociado.
Especialidad Forestal, IRENAT, Colegio de Postgraduados. Montecillo, Méx. 56230.
México.
Resumen: Con el fin de producir semilla genéticamente mejorada para sus programas de
reforestación, Smurfit Cartón de Colombia (SCC) ha establecido 80 ha entre huertos y
rodales semilleros correspondientes a 10 especies de coníferas y latifoliadas. Entre ellas el
P. oocarpa, P. maximinoi y P. tecunumanii ocupan el 18% del total plantado en áreas de
producción de semilla, ubicados entre los 2° 30’ y 3° 49’ latitud norte y entre los 1550 y
1800 metros de elevación. El objetivo de este informe es presentar la producción de semilla
alcanzada por dichas especies a lo largo del tiempo, así como los resultados obtenidos en el
último muestreo de semillas a partir de polinización abierta realizado durante 1999, en
respuesta a factores fisiológicos y prácticas culturales para inducir floración. En el rodal
semillero de P. oocarpa la producción anual de semilla es de 8 kg/ha, lo que contrasta con
la abundante presencia de conos en los árboles del rodal. Los valores promedio de semillas
llenas y totales por cono fueron de 21 y 33 respectivamente, con un potencial de producción
de semillas de 139. En el huerto clonal de P. maximinoi la producción total de semilla
alcanzó un máximo de 1.2 kg/ha/año; con valores promedio de semillas llenas y totales por
cono de 15 y 24 y un potencial de producción de 135 semillas. La producción total de
semilla para el P. tecunumanii se evalúo en dos huertos semilleros, y en un rodal,
encontrandosen valores de 1, 0.5 y 1.5 kg/ha/año respectivamente. El muestreo de semillas
en estas tres áreas de producción indicó valores promedios en un rango de 8 a 26 semillas
llenas por cono y de 20 a 40 semillas totales, con un potencial de producción oscilando
entre 121 y 150 semillas. Aunque el valor total de semilla encontrado en las diferentes
especies está muy por debajo del potencial de producción de semilla calculado, se observan
incrementos importantes tanto en la producción total de semilla como en el número de
semillas llenas y totales por cono, debido especialmente a factores como edad y prácticas
de manejo implementadas, ya que otras condiciones ecológicas que están directamente
relacionadas con la producción de semilla, aún no han sido evaluadas.
CAUSES AND CONSEQUENCES OF SHOOT BORER (Hypsipyla grandella)
ATTACK IN A MAHOGANY PROVENANCE STUDY IN PUERTO RICO. Sheila
E. Ward and Darlene Waterman
(seward@caribe.net)
International Institute of Tropical Forestry, USDA Forest Service, PO Box 25000, Río
Piedras, Puerto Rico 00928-5000
Abstract: Both the causes and consequences of shoot borer attack in mahogany have been
the source of much controversy. A provenance study begun in the 1960s by the USDA
Forest Service of different populations and species of mahogany was used to address these
issues. Seed was harvested from a series of populations in Central America and the
Caribbean and planted in Puerto Rico and the U. S. Virgin Islands, across an array of
environments ranging from dry to wet forest. Trees were periodically measured from 1965
to 1993. Canopy cover at the site of a test plantation appeared to have more influence on
shoot borer attack than life zone or soil type. Attack rates varied greatly between 1967 and
1971, from an overall mean of .36 (s. d. 0.48) attacks per tree in 1969 to a low of .036 (s. d.
0.19) attacks per tree in 1970. Tree height accounted for at most 12% of the variation in
attack, and tree growth rate accounted for very little. The relationship between height or
growth rate and attack varied widely between years and across sites and genetic sources.
Shoot borer attack between 1967 and 1971 had minimal effect on subsequent height
growth, height in 1979, and branching, and accounted for 11% of the variation in height of
lowest fork and 8% of the variation in tree form in 1986. Pruning appeared to mitigate the
effects of attack at least partially. We concluded that genetic variation in susceptibility and
tolerance in this trial was either minimal or unstable, with more variation attributable to
environmental effects. Future efforts may be better concentrated on appropriate site
selection and silivicultural management of the shoot borer. We proposed a model
integrating different factors that affect shoot borer attack by their impact on shoot borer
demographics and tree attractiveness.
PREDICCIÓN DEL RENDIMIENTO Y TURNOS DE ROTACIÓN PARA
PLANTACIONES DE CAOBA EN QUINTANA ROO, MÉXICO. Xavier García
Cuevas.
C. E. San Felipe Bacalar. Km. 50 Carr. Chetumal-Cancún. Apdo. Postal 182.
Chetumal, Q. Roo. 77000. Tel: (983) 42235. Fax: (983) 20167. E-mail:
inifapqr@prodigy.net.mx
Resumen: En el manejo de recursos forestales, el crecimiento y rendimiento son de
vital interés para la planeación de actividades. Para ello, la distribución de diámetros
como atributos de un rodal, es fundamental para la predicción del rendimiento
maderable a través del tiempo, ya que las dimensiones de los árboles, determinan en
gran medida el precio de mercado de la madera, su destino, las adaptaciones
tecnológicas de la industria y la ganancia que de ella se pueda obtener. En un régimen
de plantación y corta total, la principal decisión que se debe de realizar, es la de
estimar el tiempo en que la masa alcanza la condición de madurez. A este periodo de
tiempo se le conoce como turno. Algunas consideraciones que hay que hacer para la
definición del turno son: que la mayoría de los árboles alcancen la mínima dimensión
cosechable, que hayan alcanzado los máximos ritmos de crecimiento o que maximicen
los rendimientos económicos. En el Campo Experimental "San Felipe Bacalar",
Quintana Roo, México, se elaboró un modelo de predicción para plantaciones de
caoba, con el objetivo de modelar la distribución diamétrica, predecir la distribución
del rendimiento volumétrico a diferentes edades y fijar turnos de corta. Se utilizó
información de 4306 árboles de uno hasta 34 años de edad, provenientes de
plantaciones de densidad variable. Se estimaron los parámetros de la distribución
diamétrica de cada plantación mediante la función de distribución de probabilidades
Weibull. Se ajustaron modelos de regresión para estimar o recobrar los parámetros
Weibull a edades proyectadas. Para el cálculo de la distribución de frecuencias por
categoría diamétrica, se integra la función Weibull tomando en cuenta los límites
inferior y superior de cada categoría. Las probabilidades para cada categoría
diamétrica se multiplican por el número de árboles “N” para tener la frecuencia de
árboles por categoría y se integran otras relaciones funcionales y se proyecta el
rendimiento. Con las proyecciones se construyen las tablas de rendimiento
volumétrico promedio y distribución de productos cualquier edad deseada. En estas
tablas se tabulan las categorías diamétricas, número de árboles por hectárea, el
diámetro cuadrático, la altura total el área basal y volumen por unidad de superficie
para las edades deseadas. Este estudio sugiere que a la edad de 30 años, se esperaría
tener plantaciones con 481 árboles por hectárea, diámetro cuadrático de 29.78 cm,
altura promedio de 15.20 m, un área basal por de 21.5965 m²/ha y volumen de
339.0133 m³/ha. El turno industrial se fija en 30 años, cuando se tiene el suficiente
volumen (167.7108 m³/ha, que equivale al 49.47% del volumen total) de árboles
mayores de 30 cm, requeridos por la industria. Para determinar la edad exacta del
turno técnico, se tiene que satisfacer la condición de igualdad de ICA = IMA, lo cual
se determina en 26 años. La madurez financiera es determinada cuando el crecimiento
corriente expresado en porcentaje, se iguala a una tasa de descuento de mercado y
utilizando una tasa de descuento de 14%, lo anterior ocurre a los 30 años.
El Compendio forestal: Un sistema de apoyo a la toma de decision …. Jacques Trencia.
Canadian Forest Service-Science Branch. 580 Booth, Ottawa, ON. K1A 0E4. Tel:
(613) 947-901. Fax: (613) 947-9090. E-mail: jtrencia@nrcan.gc.ca
PRESENTATION PROVIDED
La toma de decisiones aprovechando las fuentes más recientes de informaciones
constituye un desafio en el manejo forestal. La disponibilidad inmediata de fuentes
reconocidas de conocimientos suele ser un elemento esential para los científicos del
campo forestal. Se ilustra este concepto con un ejemplo abarcando un rango ancho de
varios tipos de informaciones.
El Compendio Forestal aprovecha el concepto tradicional de monografías sobre
especies usando las informaciones las más recienes y completas en un diseño multi
media. Se combina textos detallados por expertos sobre especies forestales tratando de
características biológicas y silvícolas e incluyiendo ilustraciones, mapas, un sistema de
informaciones geográficas, una base de datos taxonómicos sobre más de 20,000
especies, un glosario multilingue sobre dasonomía y diciplines relacionadas,
bibliografías, resúmenes de publicaciones científicas, un registro de provedores de
semillas, estadísticas de dasonomía sobre países y documentos seleccionados de varias
organisaciones internacionales. Además, el Compendio incluye un sistema de
selección de especies para usos en dasonomía y en sistemas agroforestales. El módulo
global incluye también informaciones detalladas sobre 1,200 especies de bosques
tropicales y templados así como informaciones principales sobre 22,000 especies.
El diseño del programa de computo usa la tecnología de base de datos relacionadas,
vínculos flexibles, una capacidad de anotación por el usuario, sitemas de
informaciónes geográfica y taxonómica.con una arquitectura abierta facilitando
connexiones con sistemas externos. El Compendio forestal disponible en forma de CDROM con vínculos a la red electrónica mundial ha sido desarollado como parte del
programa de compendios de CAB International de una duración de 3 años
aprovechando el apoyo de un consorsio de desarollo internacional incluyendo varias
organisaciones nacionales e internacionales. La sustentabilidad del sistema y la
actualisación del sistema son elementos claves de la planeación del proyecto.
ADAPTATION & CLIMATE CHANGE
ADAPTACIÓN Y CAMBIO CLIMÁTICO
GENECOLOGY AND ADAPTATION OF DOUGLAS-FIR TO CLIMATE
CHANGE. Brad St. Clair1, Ken Vance-Borland2 and Nancy Mandel1
(bstclair@fs.fed.us), (ken.vance-borland@orst.edu) and (nmandel@fs.fed.us)
PRESENTATION PROVIDED
1
USDA Forest Service, Pacific Northwest Research Station, 3200 SW Jefferson Way,
Corvallis, Oregon 97331 USA 2Department of Forest Science, Oregon State University,
Corvallis, Oregon 97331 USA
Abstract: Results from a common garden study of coastal Douglas-fir (Pseudotsuga
menziesii var. menziesii) from western Oregon and Washington were used to explore the
relationship between genetic variation and recent climates of seed sources. Models
developed from canonical correlation analysis were used to create maps of current
geographic genetic variation using geographic information systems (GIS). Additional maps
were created to show the values of traits representing genotypes that would be best adapted
to changed climates given climate predictions for the years 2030 and 2095 from two
widely-accepted climate models. Differences between current and future genetic maps
represent maladaptation as a consequence of climate change assuming that current
populations are maximally adapted to recent local climates. Relative risk of maladaptation
was measured as the proportion of individuals within the native population that do not
overlap with the population that would be best adapted to the site. The results indicate that
by 2030 native populations will have a relative risk of maladaptation of 0.27 to 0.30. These
values are within the acceptable levels of risk for seed transfer from earlier studies. By
2095, the risk of maladaptation increases to 0.54 or 0.70, depending on the model. Values
of 0.70 may be considered high; nevertheless, 30 percent of the population will overlap
with a population that may be considered best adapted to the future climate. The present
population appears to have enough genetic variation present that it may be expected to
evolve into a new optimum through natural selection or migration. Current populations,
however, may be less productive than potential best adapted populations, and productivity
may be enhanced by moving populations from current warm to cooler sites (e.g., moving
populations from low to high elevations). GIS was used to indicate current native
populations that may be expected to be best adapted to particular sites in the future.
ADAPTIVE PHYSIOLOGICAL AND MORPHOLOGICAL RESPONSE OF RED
SPRUCE, BLACK SPRUCE AND THEIR HYBRIDS. J.E. Major, A. Mosseler, D.
Barsi and M. Campbell
(jmajor@nrcan.gc.ca)
Natural Resources Canada, Canadian Forest Service, Atlantic Forestry Centre, PO Box
4000, Fredericton, NB, Canada, E3B 5P7
Abstract: Across northern parts of its geographic range, red spruce (Picea rubens Sarg.)
lives in sympatry with the transcontinental black spruce (Picea mariana (Mill.) B.S.P.).
The two species appear closely related as they can be artificially hybridized (Manley and
Ledig 1979) and are similar in morphology (Manley 1971) as well as isozyme (Eckert
1989) and molecular marker (Bobola et al. 1992, Perron et al. 1995) profiles. Estimates of
the extent of hybridization and/or introgression range from medium (Bobola et al. 1996a,
Morgenstern and Farrar 1964, Manley 1972, Khalil 1987, Fowler et al. 1988) to low
(Gordon 1976, Manley and Ledig 1979). Hybrids, and introgressed individuals exist in
nature. However, the two species have contrasting ecological characteristics and roles; red
spruce is shade tolerant, late successional species largely confined to mesic sites while
black spruce is an intolerant, early successional species often found on extreme sites, both
very wet and very dry. In addition, because of past forest practices, red spruce has been in
decline over the majority of its range. It has been estimated that there are now currently 1/5
to 1/10 the number of red spruce compared to pre-European colonization. Red spruce cones
were collected in the fall 1996 from the provinces of Ontario, New Brunswick and Nova
Scotia. This material was grown with black spruce collected from the same areas. In
addition, hybrids from controlled crosses created at the Acadia Forest Experiment Station,
were grown together in Fredericton, New Brunswick, Canada (46° N, 66° 15' W). During
1998 and 1999, we conducted measurements to explore physiological response of red
spruce, black spruce and their hybrids. Summary results from growth and adaptive
physiological response will be reported.
EFFECTS OF CLIMATE ON WEEKLY DIAMETER GROWTH OF 9
BALCYPRESS (Taxodium distichum (L.) Rich) PROVENANCES. P.J. Young and
J.L. Chambers
(pyoung2@lsu.edu) and (jchamb@lsu.edu)
LAES, Louisiana State University, Agricultural Center, Baton Rouge, LA. 70803
Abstract: Long-term acclimation of a species to local environmental conditions leads to
genetic adaptations that allow trees to optimize growth within the normal range of climatic
variation that they are likely to experience. Evidence of global warming has led to concerns
over how trees might respond. While, provenance tests have traditionally been used to
assess the genetic potential of trees grown from seed collected from different geographic
locations, researchers have recently suggested that provenance tests may be used to predict
how local populations of trees may respond to a changing global climate. The objectives of
this study were to examine how diameter growth of 9 provenances of baldcypress
(Taxodium distichum (L.) Rich) trees might vary in response to climate change. We
installed dendrometer bands on 600 19-year old trees in the winter of 1999. Timing of leaf
expansion was recorded. Band changes were recorded on a weekly basis. Correlation
analysis of data showed significant differences among provenances in time of leaf
expansion and weekly growth rates. Provenances also showed differential responses to
climate variables. Regression of climate variables with weekly growth yielded an R 2 of
~.42 when the full growing season was examined. However, when the growth period was
divided into four periods: growth initiation, increasing period of maximum growth,
decreasing period of maximum growth and growth cessation, comparison of climate
parameters with weekly growth explained 75-98% of the growth variation. Assessing
potential climate change effects will require more scrutiny of growth responses. We will
discuss potential problem of dealing with seasonal data.
DIVERSITY AMONG F1 PROGENY ALLOWS RAPID SPECIES ADAPTATION TO
CLIMATIC TEMPERATURE CHANGE. R.S. Criddle1, J. N. Church2, M. Bacca3,
Lorraine Wiley4 , and L. D. Hansen5
(rscriddle@ucdavis.edu), (jnchurch@ucdavis.edu), (mjbacca@prodigy.net),
(lorraine@csufresno.edu) and (ldhansen@chemdept.byu.edu)
1
Section of Molecular and Cellular Biology, University of California, One Shields Avenue,
Davis CA, USA, 95616 2Agricultural and Environmental Graduate Group, Department of
Environmental Horticulture, University of California, One Shields Avenue, Davis CA,
3
4
USA, 95616
Simpson Timber Company
Department of Biology, Fresno State
5
University, Fresno CA, 93740-9999
Department of Chemistry and Biochemistry,
Brigham Young University, Provo UT, USA, 84602
Abstract: Inheritance of growth rate responses to temperature is an important determinant
of how ectothermic species’ geographic distributions may change in response to climate
change. However, variability among progeny in the growth rate vs. temperature responses
has been difficult to define because of the impracticality of obtaining quantitative
measurements of this characteristic for large numbers of individual progeny. In this study,
growth rate-temperature responses among the F1 progeny of inter- and intraspecies crosses
of eucalypts were determined from metabolic rate measurements and calculation of the rate
of storage of chemical energy by the reaction: photosynthate  structural biomass (i.e.
growth rate) as a function of temperature. The F1 progeny of all inter and intraspecies
crosses of eucalypts examined have large variation in metabolic rate and growth rate.
Viable growth temperature ranges for individual progeny may be broader or narrower than
the parent plants, with optima shifted to either higher or lower temperatures. Because plant
growth rate response to temperature is a primary determinant of the fitness of genotypes for
growth in a specific environment, selection among the widely divergent F1 progeny by
extant environmental temperature conditions provides a means to rapidly shift species
growth rate responses to changing temperature conditions.
AIR POLLUTION EFFECTS ON WINTER ADAPTATION IN YELLOW BIRCH.
R. M. Cox1. X-B. Zhu2. and J. W. Malcolm1
1
Natural Resources Canada - Canadian Forest Service, Atlantic Forestry Centre, P.O. 4000,
Fredericton, N.B. E3B 5P7, Canada. Tel1,2: (506) 452-3532, Fax1,2: (506) 452-3525, Email1 rcox@nrcan.gc.ca.
2
Faculty of Forestry and Environmental Management, University of New Brunswick,
Fredericton, E3B 6C2, Canada. E-mail: z7a6@unb.ca
Abstract: Early spring growth gives birches a competitive advantage during their
establishment after forest disturbances. This is achieved by the use of previous years wood
to conduct the water to the developing leaves. This strategy, however, is risky as birch
wood was shown to become air filled during the winter freeze-thaw cycles, requiring
refilling by way of root pressure development in the spring. This risky strategy requiring
healthy roots has served birches well in the past, as their inherited adaptability has evolved
to cope with the “normals” in climate and environmental variation. Limitations to this
adaptation were only apparent in response to rare extreme events such as the wide range
birch decline of the 1930's-1950's. Global change, however, has increased the number of
interactive stresses such as oxidative air pollutants, nitrogen and acid deposition, which can
change root and shoot frost hardiness, root/shoot biomass ratios and reduce the carbon
resources of the plant. These effects can predispose the plants to winter damage caused by
freeze thaw cycles. These predispositions together with the predicted global warming,
which is likely to increase winter temperatures, frequency of thaws, and removal of
insulating snow cover, may well push birches beyond their adaptive limits producing largescale declines. Such declines not only represent a loss in resource and carbon storage, but
will have consequences to forest regeneration and species composition as well as habitat.
This paper will integrate both experimental and field approaches in the development of a
biophysical / physiological model for a tree decline which includes exposure to ozone or
excess nitrogen as a factor in predisposition of yellow birch to spring dieback and decline.
Data will be presented that indicate that yellow birch seedlings treated with the excess
nitrate fertilizer lost their stem hydraulic conductivity at shorter thaws durations than those
provided with the lower level of the same fertilizers. The higher level of fertilizer also
accelerate the thaw-induced dehardening in stem segments. Preliminary data from a
summer ozone fumigation/winter thaw experiment indicate effects of the ozone on photo
synthesis, growth, and root to shoot biomass ratios. The possible implications of these
effects are illustrated in the birch decline model.
POSTERS
CARTELES
COMPARISON AND STANDARDIZATION OF FOUR SOIL CO2 EVOLUTION
MEASUREMENT TECHNIQUES UNDER LABORATORY AND FIELD
CONDITIONS. J.R. Butnor1
(jbutnor@fs.fed.us)
1
Southern Research Station, USDA Forest Service, 3041 Cornwallis Road, Research
Triangle Park, NC 27709, USA
Abstract: Accurate carbon budget models require quantification of component processes
including soil CO2 efflux. Larger scale modeling efforts typically utilize data collected
from different experiments, often using different techniques. Appropriate use of data sets
require a knowledge of the particular biases of each system in reference to a “ground truth”.
I compared two commercially available soil respiration systems, the Li-Cor 6400-09 and
the PP Systems SRC-1 (both closed chamber designs) and two custom designed systems.
The custom systems studied were the A.C.E.S (automated carbon efflux system) which
utilized an open chamber design and a closed method that uses the Li-6262 IRGA. In the
field, I observed differences among the techniques as high as 50%. To make analytical
assessments of the measurement techniques, artificial efflux tanks, in which the CO2 efflux
could be controlled and used as a standard were developed. These efflux generators were
built from large high-density polyethylene tanks 93L x 52W x 52H (cm). Soil medium (0.1
m3) was suspended over a pressure equilibrated footspace equipped with mixing fans.
Standard gases were circulated through the footspace creating a diffusion gradient across
the soil medium. Two types of soil media with different diffusive properties (gravel and
sand) were studied. I found that each measurement technique had a bias that could be
corrected for, but the direction and magnitude of the correction differed. When these
calibrations were used to correct field data, I was better able to assess the amount of
variation in the biological system.
POTENTIAL RELATIONSHIP BETWEEN 11-YEAR SUNSPOT CYCLE AND
TREE-RING CHRONOLOGY OF TWO HARDWOODS OF EASTERN CANADA.
Benoît Côté and Mohammed Idris
(coteb@nrs.mcgill.ca)
Department of Natural Resource Sciences, Macdonald Campus of McGill University,
21,111 Ste-Anne-de-Bellevue, QC, Canada, H9X 3V9
Abstract: Conflicting evidence has been reported in recent years concerning relationships
between 11–year sunspot cycle and tree ring chronology. The objective of this study was to
determine if 1. tree ring chronologies of hardwoods of eastern Canada have periodicities;
these periodicities are the same for trees of the same species or between species; and these
periodicites are related to the 11–year sunspot cycle. Analyses on tree ring chronologies
were done on the six oldest hardwoods stored in our data set of more than 100 trees.
Dendrochonolgies ranged fom 1835-1997 to 1988-1997 and were from sugar maple (Acer
saccharum Marsh.) and American beech (Fagus grandifolia Ehrh.). Sunspot data were from
the Sunspot Index Data Center, Belgium. Fourier time-series analysis were performed on
raw and transformed data. The transformation consisted of several passes of moving
average/median smoothing followed by differencing (X=X-X(lag)). Four out of six trees
showed significant periodicities ranging from 9.8 to 11.1 years. Cross-spectral computation
with sunspot numbers revealed that tree ring periodicities were associated with sun spot
numbers, squared coherency ranging from 0.46 to 0.78. Our results suggest that the
fluctuation in sun activity provide the base line for the rate of tree growth in long-lived
hardwoods of eastern Canada. Both the effects of internal and external factors are likely
superimposed on that base line to produce common chaotic tree-ring chronologies.
SITE PREPARATION TILLAGE IMPROVES LOBLOLLY PINE SEEDLING
(Pinus taeda L.) GROWTH IN THE PIEDMONT AND UPPER COASTAL PLAIN
OF THE SOUTHEASTERN UNITED STATES. M. J. Wheeler, R. E. Will, D.
Markewitz, D. M. Shirley, M. A. Jacobson
Daniel B. Warnell School of Forest Resources, University of Georgia, Athens, Georgia
30602, United States of America
Abstract: The effects of machine planting, disking, bedding and bedding + ripping on the
growth and physiology of loblolly pine seedlings (Pinus taeda L.) were assessed for a range
of sites on the piedmont and upper coastal plain of Georgia to determine the mechanisms
that drive stand growth differences that result from site preparation. Growth results after the
second and third growing seasons were similar. After the third growing season, the bed +
rip, bed, and disk treatment seedlings were significantly larger than the machine and no-till
treatment seedlings. However, a significant site x treatment interaction occurred because
the effect of disking varied by site. Most of the seedling mortality occurred during the first
growing season, with the disk treatment having the least mortality and the no till treatment
the most. Tillage treatments did not affect biomass partitioning when corrected for tree
size. Foliar nitrogen concentration measured during the third growing season was not
affected by the tillage treatments. Available soil nitrogen was not related to increased
seedling growth as initial ammonium extracted from the soil on the no-till treatment plots
was significantly greater than the other treatments, and no treatment differences were found
for the initial nitrate extracted or total nitrogen mineralized. Bulk density and soil moisture
was lower on the beds and in the disk plots. Therefore, soil nitrogen availability, plant
nitrogen concentrations, and biomass partitioning did not appear to drive the tillage
mediated growth differences. Rather improved soil physical conditions resulted in greater
exploitation of soil volume and hence, larger seedlings.
ESTIMATES OF WATER USE BY NATIVE VEGETATION: AN IMPORTANT
COMPONENT IN EVALUATING THE EFFECTIVENESS OF
PHYTOREMEDIATION. James M. Vose and Katherine J. Elliott
(kelliott@sparc.ecology.uga.edu)
Coweeta Hydrologic Laboratory, Southern Research Station, US Forest Service, 3160
Coweeta Lab Rd, Otto, NC 28763, USA
Abstract: Successful evaluation of phytoremediation requires an accurate assessment of
water uptake by plants. Vegetation on a site may be exerting considerable influence over
the hydrologic regime; thus, it may play an important role in phytoremediation. We
measured evapotranspiration (Et) and tranpiration (E) on a phytoremediation site at the
Naval Training Center (NTC), Orlando, Florida. Overstory transpiration was estimated by
measuring sapflow from nine trees in the summer and fall 1998, and spring 1999. Only
major canopy species on the site were sampled. We used the heat pulse technique which
involves inserting heated and unheated paired thermocouple probes in the xylem of
individual trees. Understory transpiration was estimated by taking leaf level stomatal
conductance (gl) and transpiration measurements with a Steady-State Porometer on 21 of
the dominant understory species. Leaf water-relations were measured two to three times
during the day and averaged to provide a daily mean. Percent cover and leaf-level
transpiration measurements were used to provide an index of water use for each understory
species. In the overstory, averaged across species, sapflow was highest in July and lowest
in November. Overall, Cinnamomum camphora used the most water followed by Pinus
palustris and Pinus elliotii. Individual tree regression models of mean hourly sapflow vs.
mean hourly climate explained 6% to 78% of the variation in sapflow rate depending on
species. Solar radiation and temperature were the most important climate variable for
predicting sapflow rate. The most abundant understory species based on percent cover
were Pentadon sp., Serenoa repens, Osmunda cinnamomea, and Polystichum sp. In
contrast, the species with the highest gl and E were Lantana camara, Urena lobata, Vitis sp.,
and Callicarpa america. Interception loss was estimated to be 31% based on the 10 storm
events sampled during the period of this study.
INFLUENCE OF INTENSIVE MANAGEMENT ON NET ECOSYSTEM
PRODUCTIVITY OF LOBLOLLY PINE (Pinus taeda). Michelle Ducharme1, Mandy
1
Tran , Lisa Samuelson1, Kurt Johnsen2, Tom Cooksey3
(duchamm@auburn.edu), (tranman@auburn.edu), (samuelson@forestry.auburn.edu),
(Kjohnsen@fs.fed.us), (tom.cooksey@Ipaper.com)
1
School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849
USDA Forest Service Southern Research Station, 3041 Cornwallis Rd., Research
Triangle Park, NC 27709 3International Paper, Southlands Experiment Forest, 719
Southlands Road, Bainbridge, GA 31717
2
Abstract: In light of concerns about potential global climate change associated with
increasing atmospheric CO2, it is important to identify sources and sinks of atmospheric
carbon and the contribution of intensively managed plantations to global carbon
sequestration. Therefore, our objective is to examine the influence of four treatments (weed
control, weed control plus irrigation, weed control and irrigation with liquid fertilizer
[fertigation], and weed control with fertigation and pest control) on above- and
belowground biomass, soil CO2 flux, and dark respiration of root, stem, and leaf in a sixyear-old loblolly pine (Pinus taeda) plantation over two years. We will present preliminary
data on the influence of intensive management on the spatial distribution of root mass, soil
CO2 flux and foliar respiration. Data will be coupled with aboveground biomass and tissue
respiration to separate autotrophic and heterotrophic components of soil CO2 flux and to
assess the ratio of carbon assimilated by photosynthesis to that lost via respiration. These
data will be used to quantify carbon sources and sinks in an intensively managed system.
Results will be used to assess the potential for intensively managed systems to sequester
atmospheric carbon and to better understand the influence of resource augmentation on
productivity of loblolly pine.
HIGH LEVELS OF GENETIC DIFFERENTIATION AMONG POPULATIONS OF
MEXICAN CONIFERS. F. Thomas Ledig1, Jesús Vargas Hernández2, and Basilio
Bermejo Velázquez3
(tledig@ucdavis.edu), (jesus.vargas-hernandez@orst.edu)
PRESENTATION PROVIDED
1
Institute of Forest Genetics, 2480 Carson Road, Placerville, CA 95667 2 Programa
Forestal, Instituto de Recursos Naturales, Colegio de Postgraduados en Ciencias Agricolas,
Montecillo, México, C.P. 56230 3 Division de Ciencias Forestales, Universidad Autonoma
Chapingo, Apartado Postal No. 37, Chapingo, México, C.P. 56230
Abstract: Conifers of boreal and north temperate North America, Europe, and Asia are
characterized by moderate to high levels of genic diversity for molecular markers such as
isozymes, although there are exceptions. Most of this diversity is present within
populations, and differences among populations constitute a small percentage of the total.
We reviewed the emerging literature on Mexican conifers to determine whether these
generalizations can be extended to them as well. All of our data refer to isozyme diversity,
and the taxa include spruces, firs, and pines. Levels of diversity are generally as high as
those in species from northern temperate latitudes, but levels of differentiation can be
several times higher in Mexican conifers. México’s extremes in topography and associated
climate mean that many species occur as insular populations. That is, populations exist in
pockets of favorable habitat that are separated by many kilometers, often of arid desert.
Migration among pockets is restricted, and populations are either small or have experienced
bottlenecks as their habitat shrunk during climate change. This favors genetic drift or
differentiation by selection. Drift and selection in isolation can lead to speciation, which
may explain why México is a secondary center of diversity for pines.
WATER AND CARBON RELATIONS OF Pinus elliottii FLATWOODS
SUBJECTED TO SEVERE DROUGHT. Timothy A. Martin
(tmartin@harm.sfrc.ufl.edu)
PRESENTATION PROVIDED
School of Forest Resources and Conservation, University of Florida, Box 110410,
Gainesville, Florida, USA
Abstract: Pine flatwoods are the most extensive type of terrestrial ecosystem in Florida,
occupying about 50% of the state's land area. Flatwoods characteristically are located in
low-lying areas, have level topography and relatively poorly-drained, acidic, sandy soil.
This research centers on a 10-year-old Pinus elliottii (slash pine) plantation growing on a
flatwoods site 20 km northeast of Gainesville, Florida. This site normally receives over
1300 mm of rain annually, evenly distributed throughout the year. Starting in fall of 1998,
the region entered a series of droughts that subjected vegetation to early growing season
(January - May) precipitation almost 60% below normal. Previous research has suggested
that water limitations seldom if ever limit carbon gain in these systems. The objective of
this study was to characterize tree physiological responses to these presumably severe water
deficits, and to determine the existence and mechanism of any limitations to carbon gain
resulting from those water deficits. The water and carbon relations of P. elliottii trees were
monitored periodically from January-May, 2000, using a variety of methods. Diurnal
patterns of light-saturated net photosynthesis, stomatal conductance, leaf internal CO2
concentration and parameters related to the maximum rate of Rubisco carboxylation (Vcmax)
and light-saturated electron transport (Jmax) were measured with a Li-6400 portable
photosynthesis system. Pre-dawn and diurnal leaf water potential was measured with a
pressure chamber. Tree sap flow was measured using Granier-type heat dissipation probes
installed in trees across the range of diameters present in the stand. Results of the research
will be discussed within the context of previous research in these systems made under less
limiting soil water conditions.
GENE CONSERVATION OF PACIFIC NORTHWEST CONIFERS: IN SITU AND
EX SITU ANALYSES. Sara Lipow1, Brad St. Clair2 and Ken Vance-Borland1
(sara.lipow@orst.edu), (bstclair@fs.fed.us) and (ken.vance-borland@orst.edu)
1
2
Department of Forest Science, Oregon State University, Corvallis, OR 97331-5752.
USDA Forest Service, Pacific Northwest Research Station, Corvallis, OR 97331
Abstract: The Pacific Northwest Forest Tree Gene Conservation Group is an ad hoc group
of forest geneticists representing government, university and private interests whose aim is
to ensure that the adaptation and evolutionary potential of important tree species in the
region are maintained. As part of this effort, we are analyzing the spatial distribution of
conserved genetic resources in eight conifer species in western Oregon and Washington.
The eight species were chosen based on their ecological and economic importance, and
because they have been most subject to genetic manipulation. Genetic resources present
both at their original location (in situ) and at some other location (ex situ) are being
evaluated. We used a GIS-based “gap analysis” approach to determine the extent and
spatial distribution of genetic resources conserved in situ. The first step was to develop
high-resolution GIS coverages showing the distribution of tree species across the landscape.
These coverages were built from models of potential natural vegetation. Coverages of
reserves were also created and overlaid onto the tree distributions to determine the locations
of protected populations of trees. The populations were then stratified into presumably
unique genetic units using a system of seed zones and ecoregions. The final analysis
showed the extent and distribution of protected populations. This approach provides more
detailed information on the gene resource status of tree species in situ than any other
approach taken to date. We have also summarized ex situ genetic resources for each
species. These resources include seed stores, provenance and progeny tests, seed orchards,
and clone banks both in western Oregon and Washington and in other countries when the
germplasm originated in western Oregon and Washington. This summary provides land
managers with accurate information required for the development of policy and
management decisions about additional gene conservation measurements that may be
warranted.
MICROELECTRODE TECHNOLOGY FOR MEASURING XYLEM SAP CO2
CONCENTRATIONS. Mary Anne McGuire and Robert O. Teskey
(mmcguire@smokey.forestry.uga.edu)
Warnell School of Forest Resources, University of Georgia, Athens, Georgia, USA 30602
Abstract: We explored the use of micro-carbon dioxide electrodes (Microelectrodes, Inc.,
Bedford, New Hampshire, USA) for direct measurement of xylem sap CO 2 concentrations.
These electrodes are constructed of glass with a replaceable 3 mm diameter Teflon
membrane tip that is filled with electrolyte solution. We tested the electrodes to determine
their characteristics and suitability for this application. Electrodes were calibrated in water
and air. Gas at known CO2 concentrations (2%, 10%, 15%) was bubbled through water in a
sealed beaker. Stable electrode response to a change in CO2 concentration was achieved in
10 to 20 minutes and was curvilinear with CO2 concentration. We used response data to
develop regression equations for converting mV output to percent CO2. Electrodes were
calibrated in humidified air in a similar manner. We then tested electrode response to
temperature. We placed the calibration apparatus in a controlled environment chamber and
recorded response of the electrodes to varying temperatures (15, 25, 35 C) at the three
gas concentrations. We developed an equation to correct for differences in electrode
response at varying temperatures. Electrode response drifts over time (several days to
weeks) and eventually degrades to an unacceptable level. In most cases an electrode can be
recalibrated several times, but sometimes the membrane must be replaced after just a few
days of continuous use. After completing our calibration experiments, we placed electrodes
in stems of yellow-poplar (Liriodendron tulipifera L.), white oak (Quercus alba L.), and
loblolly pine (Pinus taeda L.) at a field site near Athens, Georgia, USA. We recorded CO2
concentrations in the range of 2% to 10% and determined that concentration varied
diurnally. These results suggest that microelectrodes have advantages over other methods
for measuring stem CO2 concentration (Levy 1999). Microelectrodes provide real-time
output, are sensitive enough to detect diurnal fluctuations in CO2 concentrations, and can
easily be placed at different depths and heights in the stem. Our results indicate that
microelectrodes are suitable for measuring xylem CO2 concentrations in tree stems.
REGULATION OF ECOSYSEM FUNCTIONS ACROSS COMPLEX
ENVIRONMENTAL GRADIENTS IN LONGLEAF PINE (Pinus palustris)WIREGRASS (Aristida stricta) WOODLANDS. Robert J. Mitchell1, L. Katherine
Kirkman1, Stephen D. Pecot1, Carlos A. Wilson1, Lindsay R. Boring1, Joseph J.
Hendricks2, Ron Hendrick3, and James A. Vose4
1
Joseph W. Jones Ecological Research Center, Newton, GA, USA 2Department of Biology,
State University of West Georgia, Carrollton, GA, USA 3Warnell School of Forest
Resources, University of Georgia, Athens, GA, USA 4Coweeta Hydrologic Lab, U.S.
Forest Service, Otto, NC, USA
Abstract: Understanding controls on productivity across landscapes is an important area
of ecological inquiry. Longleaf pine-wiregrass (Pinus palustris Mill-Aristida stricta Michx.)
savannas occupy sites ranging from deep, xeric sandhills to the edge of wetlands.
Aboveground and belowground net primary productivity (ANPP, BNPP) of the overstory
and understory were determined across this complex environmental gradient for three
replicate sites of three site types (xeric, intermediate and wet-mesic). Soil moisture (at 30
and 90 cm) and N-mineralization (in situ buried bag incubations) was measured through an
annual cycle for three years. Soil CO2 efflux and related environmental variables were
measured for one year of the study. ANPP more than doubled across the environmental
gradient. ANPP was positively correlated with soil moisture and negatively correlated to Nmineralization (see poster by Wilson et al.). Temporal variation in overstory ANPP
(averaged across sites) ranged from 1.8-4.2 Mg ha-1 yr-1; spatial variation in ANPP
(averaged through time) ranged from 1.9-4.3 Mg ha-1 yr-1 and varied with site (p=0.0023).
BNPP fine root estimates depended on the method used. Methods unable to separate
simultaneous growth and mortality of fine roots underestimated BNPP by approximately an
order of magnitude from minirhizotron measurements. C allocation across productivity
gradients varied similarly among methods but appeared to be relatively constant when
minirhizotron estimates are used. Soil CO2 flux varied positively with NPP patterns across
the gradient (ANPP r2=0.40, p=0.067; BNPP r2=0.32, p=0.11; NPP r2=0.44; p=0.049).
Soil temperature and moisture appear to be major controls on soil CO2 flux. Finally,
frequent fire appears to increase belowground dynamics through CO2 flux, relative root
standing crop, and BNPP. We also present a new experiment that incorporates resource
additions to allow for investigations into multiple resource limitations and how these
limitations vary depending on gradient position and their impact on ecosystem function.
OVERSTORY STRUCTURE AND REGENERATION PROCESSES IN LONGLEAF
PINE-WIREGRASS FORESTS. Robert J. Mitchell1, Brian J. Palik2, Robert H. Jones3,
Mou Pu4, Stacy Hurst1, Stephen D. Pecot1, Michael A. Battaglia4, and Glen L. Stevens3
1
Joseph W. Jones Ecological Research Center, Newton, GA, USA 2USDA Forest Service,
Forestry Sciences Laboratory, Grand Rapids, MN USA 3Department of Biology, Virginia
Polytechnic Institute and State University, Blacksburg, VA USA 4Department of Forestry,
Virginia Polytechnic Institute and State University, Blacksburg, VA USA
Abstract: Silvicultural methods used to meet objectives of ecosystem management often
include green tree retention, or a reserve shelterwood, in order to maintain components of
mature stand structure. The competitive environments and mechanisms that influence
regeneration in such systems differ substantially from those under even-aged management.
We initiated a study in a 65-year-old longleaf pine forest to address the effects of residual
overstory structure and competing herbaceous vegetation on survival and growth of
longleaf pine seedlings. Stands were harvested to similar residual basal areas using singletree selection, small group (~0.25 ac) selection, and large group (~0.5 ac) selection. An
uncut control stand was used as a reference. Twenty-five subplots encompassing the range
of overstory abundance index (OAI) were installed. Ten one-year-old containerized
longleaf pine seedlings were planted at 2 quadrants (2 by 2-ft spacing) per subplot, one side
receiving a glyphosate application to remove the understory. Soil resources and light
availability were quantified over a two-year period, as well as seedling survival, size, and
growth. Trench plots were also installed across a range of OAI. The overstory and
understory facilitated survival of longleaf pine seedlings but competed with them relative to
seedling growth. Seedling survival increased positively with OAI and in the presence of
understory. Microclimate changes, i.e., lower soil temperature and relative humidity, in the
shade appeared to result in facilitation rather than increased soil moisture during a severe
drought. Seedling growth was negatively influenced by OAI largely through attenuation of
light by the understory. Soil N was increased at low OAI but only when the understory was
absent. Root gaps created through overstory removal appear to be filled quickly by
understory plant communities. Finally, trenched subplots preventing overstory root
encroachment resulted in a substantial hardwood response which negatively affected
growth and survival of longleaf pine seedlings.
CARBON – FINE ROOT ALLOCATION AND TRANSFER AT ECOSYSTEM
SCALES (C-FATES). Durwin C. Carter1, Joseph J. Hendricks1, and Robert J.
Mitchell2
1
State University of West Georgia, Carrollton, GA, USA
Research Center, Newton, GA, USA
2
Joseph W. Jones Ecological
Abstract: Accurately quantifying fine root dynamics, particularly C allocation to fine root
tissues, is pivotal to understanding forest structure and function. Previous attempts at
estimating belowground production utilized 1) indirect methods lacking the ability to
account for continuous rates of growth, death, or herbivory attributed to fine roots or 2)
nutrient balances with unsubstantiated assumptions. Recent methods, i.e., minirhizotron
imaging, allow for direct observation of root genesis, growth, and mortality. Direct
observation allows for a more quantitative assessment of critical controls on belowground
C allocation. Carbon allocation to fine roots and their controls has been addressed;
however, generally accepted explanations have not been presented. We present a
conceptual C-FATES (Carbon-Fine root Allocation and Transfer at Ecosystem Scales)
model that models C allocation to fine roots while accounting for simultaneous rates of
production, mortality, and herbivory. The study took place in a 15-year-old longleaf pine
plantation. Three treatments were randomly assigned in a multi-factorial design:
fertilization addition to increase root respiration; biocide additions to limit herbivory by soil
insects and nematodes; and foliage scorch to reduce carbon flux belowground. For direct
observations of root turnover rates, minirhizotron tubes were used. Nematode assessments
and grub populations were collected to observe differences across treatments. Soil larvae
populations numbered around 6.05 kg ha-1 and 10.40 kg ha-1 for the two collection
periods. Nematode types included Criconemoides, Xiphinema, Meloidogyne, and
Pratylenchus; however, numbers were considerably low before and after biocide additions
with maximum levels of 22 Criconemoides individuals per 100 cc of soil. Soil larvae
populations were not affected by the recommended biocide additions of 22.71 liters per
acre. Root N concentrations were not significantly different across fertilization treatments.
Future work will quantify C allocation patterns as fertilization continues and is influenced
by the foliage scorch treatment to reduce C source strength.
ENVIRONMENTAL CONTROLS ON LEAF AND CONOPY CONDUCTANCE OF
LONGLEAF PINE (Pinus palustris Mill.). Robert N. Addington1, Robert J. Mitchell2,
and Lisa A. Donovan1
1
Department of Botany, University of Georgia, Athens, Ga., USA
Ecological Research Center, Newton, Ga., USA
2
Joseph W. Jones
Abstract: Longleaf pine (Pinus palustris Mill.) savannas dominated the Atlantic and Gulf
Coastal Plains of the Southeastern United States prior to European settlement. Within what
remains of its historic range, longleaf pine is widely distributed from xeric sandhills to
poorly drained flatwoods adjacent to wetlands. Soil water availability appears to be the
primary driver of net primary productivity along this gradient, but little is known about the
role of soil moisture in regulating biosphere-atmosphere energy exchange. Furthermore,
little work towards modeling atmospheric and soil moisture controls on water flux has been
done in this system. We initiated a study at the Jones Ecological Research Center that will
investigate atmospheric and soil moisture controls on leaf and canopy conductance of
natural longleaf pine stands. We selected sites representing the extremes of soil moisture
conditions on which longleaf pine occurs at the Jones Center. We are estimating canopy
conductance from sapflow measurements and leaf-to-air vapor pressure deficit for selected
individuals on each site, and we are measuring leaf conductance and water potential on a
subsample of trees accessible by canopy access towers. Additionally, we are measuring
temporal variation in atmospheric demand and soil moisture content to determine the
response of canopy conductance to increasing water deficit and to determine if that
response differs according to site. Preliminary results from a comparison of stable carbon
isotope ratios suggest that water use strategy and stomatal response to water stress differ
markedly according to site. Relationships between soil moisture content, leaf water
potential, and leaf conductance will be presented, and drought effects on stand-level canopy
conductance will be discussed. Relevance to climate change models and limitations of the
methods will also be discussed.
ASSESSING THE PATTERNS AND CONTROLS OF FOLIAR LITTER
DECOMPOSITION LONGLEAF PINE-WIREGRASS ECOSYSTEMS. Lindsay R.
Boring1, Joseph J. Hendricks2, Carlos A. Wilson1, and Mary L. Cobb1
1
Joseph W. Jones Ecological Research Center, Newton, GA, 31770 USA 2State University
of West Georgia, Carrollton, GA, 30118 USA
Abstract: Prescribed burning is an important management tool in longleaf pine-wiregrass
ecosystems. This recurrent disturbance may have a substantial impact on nutrient cycles,
particularly N, and thus the long-term productivity of these forests. To more accurately
assess and predict burning impacts, it is important to gain an improved understanding of the
factors regulating the mass and nutrient concentration of fine fuels in the understory. The
primary objectives of this study were to assess the patterns and controls of biologically
mediated foliar litter decomposition and develop mathematical models to predict litter mass
loss and nutrient cycling dynamics in these ecosystems. In Fall 1995, freshly senesced
litter from seven species, representing a broad range in tissue substrate quality, were
collected, placed in mesh bags, and incubated in the field. Litter bags were placed directly
on the forest floor and in elevated positions to simulate wiregrass structure. Periodically,
samples were retrieved and analyzed for dry mass and chemical composition. After two
years, species mass loss patterns exhibited the standard exponential decay function, and the
decay constants were most strongly correlated with the initial P concentration of the tissues
(R2 = .89). Mass loss rates of the elevated litter were approximately one half of the values
measured for corresponding forest floor tissues. While most tissue types initially
immobilized N, all species exhibited a net N release by the end of the first year. Also,
forest floor tissues exhibited significant inverse linear relationships between N
concentration and percent mass remaining (R2 values from .70 - .99). These decomposition
results were coupled N flux data from associated studies to assess the potential impact of
different burning regimes on the N balance of these ecosystems and to identify important
questions for future research.
NITROGEN DYNAMICS IN A LONGLEAF PINE-WIREGRASS WOODLAND.
Carlos A. Wilson1, Robert J. Mitchell1, Joseph J. Hendricks2, and Lindsay R. Boring1
1
Joseph W. Jones Ecological Research Center, Newton, GA, 31770 USA 2State University
of West Georgia, Carrollton, GA, 30118 USA
Abstract: In June 1995, we initiated a study to assess the patterns and controls on N
mineralization across a longleaf pine-wiregrass dominated landscape, and relate them to
observed net primary productivity (NPP) patterns over a burn cycle. Xeric sites exhibited
the greatest mineralization rates as determined using buried bag incubations in the top 10
cm of soil. Net N mineralization rates were inversely correlated with both soil moisture and
aboveground NPP. Higher N availability patterns on the xeric site were due to higher levels
of nitrification, while N flux in the intermediate and wet-mesic sites were dominated
exclusively by ammonium-N. Nitrification rates declined with time since fire, and
ammonium-N production remained relatively stable over the same period. Overall, data
suggest that soil temperature and organic matter quality differences among sites may be
important drivers of both temporal and spatial patterns. Microbial biomass N (MBN)
exhibited an initial increase immediately following prescribed burning and was generally
higher in the wet-mesic site. Low rates of N mineralization were not sufficient to account
for ANPP N demand; however, initial results suggest that substantial mineralization in
deeper portions of the soil could supply this demand. This could be due to the edaphic
characteristics of this ecosystem and the influence of fire in increasing the importance of
root turnover to the soil detritus pool. Mineralization paralleled root distribution patterns
down to 1 m depth. Further investigation into the complex controls on microbial dynamics
and their interaction with belowground litter inputs in the context of N cycling are needed.
TREE RADIAL GROWTH AND UNDERSTORY VEGETATIVE PRODUCTION
IN A 30-YEAR-OLD THINNED BOTTOMLAND OAK PLANTATION. K.L.
Wharton1, J.L. Chambers1, J.S. Meadows2 and K.F. Ribbeck3
(kwharto@lsu.edu), (jchamb@lsu.edu), (smeadows@fs.fed.us)
1
Louisiana Agricultural Experiment Station, School of Forestry, Wildlife, and Fisheries,
Baton Rouge, Louisiana 70803 2Southern Hardwoods Laboratory, Center for Bottomland
Hardwood Research, P.O. Box 227 - Stoneville, Mississippi 38776 3Louisiana
Department of Wildlife and Fisheries, 2000 Quail Drive - Baton Rouge, LA 70808
Abstract: The establishment of various forest incentive and forest reserve programs in the
U.S. such as, the Conservation Reserve Program and the Wetlands Reserve Program have
led to millions of hectares being planted in oak plantations. Many of these plantations will
soon reach an age where they could benefit from thinning and other management practices
designed to increase growth and yield responses. Unfortunately, very few studies have
dealt strictly with growth responses of even-aged oak plantations to thinning. Additionally,
oak plantations provide significant habitat for wildlife, but few studies have looked at the
response of understory vegetation to thinning in closed-canopy bottomland oak plantations.
The objectives of this study were to evaluate the responses of tree radial growth and
understory vegetative production to different levels of operational thinning in a bottomland
oak plantation. This study was conducted in a 30-year-old cherrybark oak (Quercus
pagoda Raf.) plantation located at Red River Wildlife Management Area, Concordia
Parish, Louisiana, USA. We established fifteen treatment plots consisting of 20.4- by 81.6meter measurement plots with buffers of 20 meters on all sides. Treatment plots were
blocked by initial stocking (three plots per block) and assigned a thinning treatment: uncut
control, light thinning (70-75% initial stocking), or heavy thinning (45-50% initial
stocking). Understory vegetative production was evaluated using biomass clipping and
Aldous deer browse surveys conducted at twenty points within each treatment plot.
ANOVA showed no significant differences in first year radial growth among thinning
treatments (95% confidence level). However, there were highly significant differences in
understory vegetative production among thinning treatments (p=0.0005). So, while thinning
intensity did not have a significant effect on radial growth the first season following
thinning, it had a highly significant effect on understory vegetative production. Other
effects of thinning will be discussed as well.
ROOTS CAN DRIVE GROWTH OF TREE SEEDLINGS. James E. Grissom and
Steven E. McKeand
(jegriss2@unity.ncsu.edu)
PRESENTATION PROVIDED
Department of Forestry, North Carolina State University, Campus Box 8002, Raleigh, NC
27695
Abstract: Processes occurring in the leaves are important in determining whole-tree
growth, but the importance of processes occurring in the roots is less clear. Water and
nutrient uptake are critical functions of root systems, but the genetic variation in root traits
and the impact on whole-tree growth is not well understood. A major obstacle is that
genetic effects of roots are integrally confounded with effects of leaves and other plant
parts. Our main objective was to evaluate genetic effects of roots upon tree growth by
alleviating the confounding effects of root and shoot processes. One approach is to
assemble a population of grafted plants of known genetic origins. We used a novel grafting
technique with loblolly pine (Pinus taeda L.) seedlings of contrasting growth habits to
assess rootstock effects on tree growth and biomass allocation. Seedlings of fast- and slowgrowing provenances were grafted reciprocally in all possible combinations. Seedlings
were planted on an infertile site in a split-plot design with half of the plots fertilized
periodically. After two growing seasons, rootstock effects on tree growth were large in the
fertilized treatment. The roots of the fast-growing provenance were able to drastically
increase the aboveground biomass of the constituent slow-growing provenance.
Physiological mechanisms by which the roots of the fast-growing provenance boost tree
growth appear to involve more efficient use of water and enhanced uptake of mineral
nutrients. These results show that genetic factors of tree roots can substantially influence
the physiology and growth of tree seedlings.
FINE ROOT GROWTH IN LOBLOLLY PINE SUBJECTED TO FERTILIZATION
AND CO2 TREATMENTS. Kim H. Ludovici and Lance W. Kress.
(kludovici@fs.fed.us)
PRESENTATION PROVIDED
USDA Forest Service, 3041 Cornwallis Rd., Research Triangle Park, NC 27709 USA
Abstract: Loblolly pine (Pinus taeda L.) is a rapidly growing conifer that occupies
approximately 30 million acres in the southeastern United States (USDA Forest Service
1988). Studies with loblolly pine have shown increased net photosynthesis and growth
response to CO2 enrichment (Sionit et al. 1985, Groninger et al. 1995, Murthy et al. 1995,
Teskey 1995). These aboveground physiological responses of trees will impact carbon
allocation and resource availability for belowground growth. The primary objectives of this
study were to quantify root growth (rates, longevity and distribution) under elevated CO2
conditions, and to examine interactions between site fertility and CO2 each season. Using
mini-rhizotron tubes and root ingress cores, loblolly pine root growth, longevity and
distribution were evaluated under trees exposed to elevated CO2 levels in whole tree opentop chambers. Root ingress cores were harvested every four months for two years, to enable
quantification of root length, weight, and C and N contents. A more complete harvest was
made at experiment end. It appeared that allocation was shifted from belowground to
aboveground tissue, with increases in aboveground biomass and decreases in some root
components in elevated CO2 compared to controls. Elevated CO2 treatments generally
increased root C concentration and altered root size distribution. Fertilizer treatments also
increased root C concentrations and generally decreased fine root growth. Changes in root
density, root length density, and biomass, by root component and treatment interaction, will
be discussed.
HERBACEOUS FLORA AS INDICATORS OF SUGAR MAPLE SITE QUALITY.
Stephen B. Horsley 1, Robert P. Long 2 and Scott W. Bailey 3
(shorsley@fs.fed.us), (rlong@fs.fed.us) and (swbailey@fs.fed.us)
USDA Forest Service, Northeastern Research Station 1 Forestry Sciences Laboratory, P.O.
Box 267, Irvine, PA 16329 USA 2 Forestry Sciences Laboratory, 359 Main Rd., Delaware,
OH 43015 USA 3 Hubbard Brook Experimental Forest, RFD 1, Box779, Campton, NH
USA
Abstract: Sugar maple is a keystone species in the northeastern United States and eastern
Canada. The species has been declining across the unglaciated Allegheny Plateau in
northern Pennsylvania since the 1980s. Throughout its northern range, health and growth of
sugar maple have been associated with supplies of base cations, particularly Mg and Ca.
Research in northern Pennsylvania and southern New York indicates that sites vulnerable to
sugar maple decline are those with low foliar Mg and Ca and 2 moderate to severe
defoliations in the past 10 years. Geology and soils maps can provide the general location
of base cation-poor sites, but site-specific indicators of good sugar maple site quality are
lacking. A preliminary qualitative reconnaissance of more than 80 stands in PA, NY, VT,
and NH in 1997 and 1998 resulted in a working hypothesis that herbaceous plant
communities might provide such a site-specific tool. The qualitative reconnaissance
showed that species such as wild leeks (Allium tricoccum), blue cohosh (Caulophyllum
thalictroides), maiden-hair fern (Adiantum pedatum), and hepatica (Hepatica acutiloba)
were routinely associated with healthy stands of sugar maple. In 1999 and 2000 quantitative
surveys of the herbaceous plants in 89 stands in PA, NY, VT and NH were conducted.
These northern hardwood stands were identified previously in a regional sugar maple health
assessment and were used to examine foliar and soil nutrition, radial growth, stand structure
and species composition and stand health. Herbaceous inventories were conducted during
May and July 1999 in the PA and NY stands and during July 1999 and May 2000 in the VT
and NH stands. In each stand, twenty-five 1-m2 plots were established on a systematic grid
within a 50 by 20 m area. In each 1-m2 plot, all species present were identified and the
percent cover was estimated (1, 2, 3, 4, and 5% and by 5% increments to 100%). About 300
species were identified in the 46 PA and NY stands, and over 230 species in the 43 VT and
NH stands. After all 25 plots in a stand were sampled, a random search was conducted to
identify additional species within the 0.4 ha area that enclosed the 1000 m2 area. Presenceabsence, abundance, frequency, and importance data from these stands are being used in
association with foliar and soil nutrition in an indicator species analysis. We envision the
use of site-specific herbaceous indicator species in association with forest health
monitoring to enable land managers to make timely decisions about insect suppression
efforts or other management options.
THE EFFECT OF FERTILIZATION ON GAS EXCHANGE AND GROWTH OF
MATURE LONGLEAF PINE. Anderson, P.H., and K.H. Johnsen
USDA, US Forest Service, Southern Experiment Station, Research Triangle Park, NC
27709
Abstract: Longleaf pine, (Pinus palustris), is a dominant tree found on the coastal plain
throughout the southeastern US. Stand level fertilization of pine species is being used to
increase productivity for both the wood products and pine straw industries. However, there
are indications that longleaf responds differently to fertilization than loblolly pine. The
study was conducted in Scotland County, NC on a 15-year old loblolly pine plantation,
which contains small numbers of volunteer longleaf. At age 8, we imposed a fertilization
treatment in which fertilizer was applied at an “optimal” level, measured as 1.3 % N in the
loblolly foliage. Gas exchange measures were taken bi-monthly over the course of a year
from June 24, 1999 through June 2000 on 24 trees total. Growth of 20 trees per treatment
was measured yearly beginning in 1992. Net photosynthesis and stomatal conductance
were significantly increased in fertilized trees on September 23, 1999. On all other
measurement days net photosynthesis and stomatal conductance in controls were either
similar or higher than fertilized trees and was significantly greater on May 4, 2000. Mean
net photosynthesis and stomatal conductance throughout the study was significantly greater
in control than fertilized trees. Diameter growth over the entire experiment was increased
10.6% by fertilization, although not statistically significant while height and height to live
crown were significantly increased. During the 1999 growing season diameter increment
growth was significantly greater in the control trees and differences in height increment and
height to live crown between treatments disappeared. This suggests that initial increases in
growth due to fertilization are being limited as the study progresses and can be partly
attributed to increased gas exchange and carbon assimilation. Results may be partially
explained by competition effects with loblolly pine, which has responded positively
(volume growth = 2.5 x controls) to fertilization.
MANAGEMENT IMPLICATIONS OF WHITE PINE BLISTER RUST INFECTION
AND MORTALITY THROUGH AGE 15 IN SUGAR PINE IN SOUTHWESTERN
OREGON. Richard A. Sniezko1, Andrew D. Bower1 and Ellen M. Goheen2
(rsniezko@fs.fed.us), (abower@fs.fed.us) and (egoheen@fs.fed.us)
PRESENTATION PROVIDED
1
USDA Forest Service, Dorena Tree Improvement Center, 34963 Shoreview Road, Cottage
Grove, OR 97424, USA 2 USDA Forest Service, SW Oregon Forest Insect and Disease
Service Center, 2606 Old Stage Road, Central Point, OR 97502, USA
Abstract: Six plantations of sugar pine (Pinus lambertiana) were established in the early
1980’s in southwest Oregon with seedlings from 53 families previously screened for white
pine blister rust (Cronartium ribicola) resistance. These sites were established to validate
the screening and to monitor rust infection, virulence, and mortality over time. Not all
families were planted on all sites, and a subset of 25 families represented at all six sites are
discussed here. The six sites were selected to cover a range of blister rust hazards and all
trees were inspected and measured for height, presence and location of infection, and type
and severity of damage at age 5, 10 and 15. In addition, at age 15 the number of cankers
per tree was counted, as well as the height of the highest canker. Blister rust infection
varied significantly by site at all ages, with the widest spread in site means being at age 10
(15.9 to 95.0%). Infection percentages on all sites increased dramatically between age 10
and 15, and at age 15 ranged from 77.7 to 99.1%. At age 15, percent mortality by site
ranged from 41.2 to 91.2%. The mean number of cankers per tree on all living trees varied
widely by site from 1.3 to 10.8, although due to high mortality on some sites, these means
are based on widely differing numbers of trees per site (82 to 507). Mean height of the
highest canker ranges from 59.8 to 144.5cm with 88% of all cankers below 2.0 meters.
Infection levels at age 15 on 6 additional families known to have a single dominant major
gene for resistance (MGR) range from 44.4 to 57.2%. It appears that there is little or no
evidence that a strain of rust with virulence to MGR in sugar pine is present on these sites
at this time and this will continue to be monitored in the future. The viability of planting
sugar pine in southwest Oregon will depend on several factors, including rust hazard,
effectiveness of silvicultural treatments, type and durability of resistance, and development
of virulence in the rust population.
GENETIC DIVERSITY AND RESTORATION OF A DISJUNCT PITCH PINE
POPULATION IN VERMONT, U.S.A. G.J. Hawley1, D.H. DeHayes1 and P.G.
Schaberg2
(ghawley@nature.snr.uvm.edu), (ddehayes@nature.snr.uvm.edu) and (pshaberg@fs.fed.us)
1
2
School of Natural Resources, University of Vermont, Burlington, VT, U.S.A, 05405
U.S.D.A. Forest Service, Northeastern Research Station, Burlington, VT, U.S.A, 05403
Abstract: Pitch pine (Pinus rigida Mill) in northern Vermont (VT) U.S.A. represent
marginal populations that, because of their potential genetic uniqueness, may be valuable
for the future evolution of the species. Development pressures threaten the survival of the
species in this area. Within Camp Johnson (VT Army National Guard compound), resides
one of the last relatively large populations of pitch pine; however, primarily because of the
lack of periodic fires necessary for seedling establishment, there is little pitch pine
regeneration in this stand. Establishment of regeneration via planting could be problematic
because seedlings from outside the area may not be adapted to northern VT and the
introduction of outside germplasm could compromise the genetic uniqueness of the existing
population. Objectives were to: 1) evaluate the genetic diversity of pitch pine at Camp
Johnson; 2) estimate the genetic uniqueness of that population compared to other marginal
and central populations; 3) estimate current levels of inbreeding; and 4) provide a genetic
perspective to a restoration plan. Genetic assessments using starch gel electrophoresis
indicate that relatively large differences in gene frequency exist among pitch pine
populations and that the Camp Johnson population is genetically unique. Thus, if seedlings
from outside Camp Johnson were used for restoration, gene frequencies would be altered in
subsequent generations and the future adaptation and evolution of this population could be
jeopardized. Because there was no evidence of low genetic variability or higher than
normal levels of inbreeding, and because germination is adequate in Camp Johnson pitch
pine, we recommended that germ plasm from Camp Johnson be used to restore pitch pine
here. Restoration was initiated in 1998. Seedlings grown from Camp Johnson pitch pine
seed were outplanted after several controlled burns to prepare the seedbed. Seedling
survival is periodically assessed and additional plantings are planned.
CALCIUM DEPLETION: A THREAT TO FOREST HEALTH AND
SUSTAINABILITY? G.J. Hawley1, D.H. DeHayes1 and P.G. Schaberg2
(ghawley@nature.snr.uvm.edu), (ddehayes@nature.snr.uvm.edu) and (pshaberg@fs.fed.us)
1
2
School of Natural Resources, University of Vermont, Burlington, VT, U.S.A, 05405
U.S.D.A. Forest Service, Northeastern Research Station, Burlington, VT, U.S.A, 05403
Abstract: Recent evidence indicates that numerous anthropogenic factors can deplete Ca,
an essential plant nutrient, from forest systems. Available Ca is important to membrane
structure and function, and serves as a second messenger in the perception and transduction
of environmental stimuli and stress signals. In its’ messenger role, Ca movement across
membranes initiates plant response and defense systems to an array of environmental
stresses including temperature perturbations, drought, salt, fungal pathogens, and insects.
We have demonstrated that acid deposition directly leaches plasma membrane-associated
Ca (mCa) from red spruce (Picea rubens) mesophyll cells. This loss of mCa destabilizes
cells and increases their susceptibility to the freezing injury responsible for red spruce
decline in the northeastern U.S. Our data now indicate that acid-induced perturbations of
mCa and membrane stability can also occur in other tree species (e.g, eastern hemlock
(Tsuga canadensis) and balsam fir (Abies balsamea)), and that soil-based treatments can
independently limit mCa accrual and alter membrane integrity. These findings suggest that
mCa disruptions may be more pervasive than the direct acid-induced foliar alterations
already noted for red spruce. We hypothesize that anthropogenic disruptions of biologically
available Ca impair the ability of trees to recognize and respond to environmental stress,
predisposing forests to decline. Although this hypothesis is not centered on any one species
or decline, we are intrigued about the potential predisposing influences of Ca perturbation
on the well-documented decline of sugar maple (Acer saccharum). Several environmental
factors (notably drought, insect defoliation, and freezing injury) as well as nutritional
deficiencies (especially Ca) have been implicated with maple decline. Considering the
importance of Ca in plant responses to stresses associated with maple decline, it is plausible
that disruptions of Ca have compromised the ability of sugar maple forests to respond to
secondary stressors that would otherwise pose no catastrophic threat.
UN ÍNDICE DE HUMEDAD Y TEMPERATURA DEL SUELO
CORRELACIONADO CON LA SOBREVIVENCIA DE PLÁNTULAS. Miguel
Angel Capó Arteaga
Profesor Investigador, Depto. Forestal, UAAAN, Saltillo, Coahuila, México
Resumen: Uno de los mayores retos es el diseño de parámetros que nos permitan aumentar
nuestra capacidad de diagnosticar o predecir que tipo de ambientes son favorables para la
productividad vegetal. En el campo de la investigación forestal se requiere clasificar
rodales según el riesgo que representan para el establecimiento de plantaciones forestales.
Capó (1987) y Capó y Newton (1991) propusieron un índice de condiciones del suelo
reportaron una alta correlación entre el índice y la sobrevivencia de cinco especies de
coníferas en el sureste de Oregon. Las mediciones que se requiere para obtener los datos se
hacen colocando un bloque de yeso a 45 cm de profundidad y midiendo la resistencia
eléctrica de los bloques mediante un aparato tipo Boyoucos. La temperatura se midió a 30
cm de profundidad con un termómetro de suelo. En el caso de los resultados reportados por
Capó y Newton (1991) el promedio de los índices obtenidos de las mediciones mensuales
de los meses Mayo a Septiembre mostraron la más alta correlación con la sobrevivencia,
excepto para la especie Pinus ponderosa que fue bastante insensible al estrés hídrico y
térmico. En una plantación de Pinus en la Sierra Madre Oriental, en Arteaga, Coahuila
obtuvimos datos para la construcción del índice de condiciones del suelo del primer año de
plantado y la correlación con la sobrevivencia del segundo año de cuatro especies y con la
sobrevivencia promedio.
Conclusiones.
1) Deben desarrollarse esfuerzos encaminados a facilitar el diagnóstico de los sitios
forestales y predecir la sobrevivencia de la regeneración, sea natural o inducida.
2) El uso de un índice que combine la disponibilidad de humedad y la temperatura del suelo
ofrece amplias perspectivas de aplicación en el campo de la Ecología Vegetal y la
Silvicultura. El efecto de la eliminación de la vegetación competidora, en términos de
humedad del suelo, puede ser detectado con este método sencillo y fácil de aplicar.
ESTADO ACTUAL DEL BOSQUE DE Pinus maximartinezii, UN PIÑONERO EN
PELIGRO DE EXTINCIÓN. Miguel Angel Capó Arteaga1 y Edmundo Lara
Rodríguez
1
Profesor Investigador, Dept. Forestal, UAAAN.
Resumen: Pinus maximartinezii es una especie endémica de Juchipila, Zacatecas, México,
que se distribuye en un área no mayor de 10 km2 entre los 21° 20’ y 21° 23’ Latitud Norte y
los 103° 12’ y 103° 15’ Longitud Oeste. El suelo, de textura gruesa y pH ácido, es de
origen ígneo. El clima es continental con lluvias en verano. La precipitación fluctúa entre
750 y 900 mm anuales. La temperatura media anual es de 18°C. Con el propósito de
conocer la estructura y distribución de los rodales de esta especie, durante 1995 se realizó
un inventario en 415 ha, ubicando 54 sitios circulares de muestreo de 1000 m² cada uno. Se
identificaron cuatro rodales. En el poster se muestra la densidad media de árboles para cada
rodal. El número de árboles con conos maduros y el número de conos por árbol se
presentan también. Sólo el 20.4% de los árboles presentan conos maduros. El número de
conos por árbol es de 4.6, y cada cono produce en promedio 100 gr de semilla. La densidad
de la regeneración natural (árboles menores de 130 cm) es baja pues apenas es de 333
individuos por hectárea en promedio, pero tres de los rodales tienen menos de 220
individuos/ha. La colecta de semilla.
EVALUACIÓN TEMPRANA DE PROCEDENCIAS-PROGENIES EN CAOBA
(Swietenia macrophylla King). Bartolo Rodríguez Santiago1, Kevyn Wightman2,
Sheila Ward3 y Jeremy Haggar2
1
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias. A.P. 182
Chetumal, Quintana Roo, Méx. 77000. e-mail: inifapqr@prodigy.net.mx
2
CATIE-mip, Nicabox 112, PO Box 2333, Miami, Florida 33152.
3
International Institute of Tropical Forestry, PO Box 25,000, San Juan Puerto Rico. e-mail:
seward@caribe.net
Resumen: En México y América Latina la caoba (Swietenia macrophylla King), es la
especie forestal económicamente más importante. En los últimos años, las existencias
reales de esta especie han disminuido considerablemente. Lo anterior ha inducido el interés
por su aprovechamiento, cultivo y preservación. Sin embargo, la mayoría de los viveros
forestales que apoyan los Programas de Producción Masiva de Plantas de caoba y cedro
(Cedrela odorata), utilizan semillas de origen desconocido. Los resultados que se presentan
son parte de un Proyecto de Colaboración que tiene la finalidad el estudio y preservación de
los recursos genéticos, entre ello, la caoba. Se colectaron semillas de 100 árboles
localizados en la Península de Yucatán, agrupados en 5 procedencias. Cada procedencia
tuvo entre 6 y 51 familias. El transplante se realizó en bolsas de polietileno negro. Se
establecieron ensayos en 3 diferentes sitios. En campo, las plantas se establecieron en un
diseño experimental bloques completos al azar con 5 repeticiones. El número de familias
plantadas en cada sitio varió entre 47 y 56, con 36 familias presentes en los tres sitios. Se
registraron mediciones y observaciones de altura total, tasa de crecimiento en altura, ataque
de Hypsipyla grandella, ramificación y vigor de las plantas. A nivel de Procedencias se
utilizó la técnica de Promedios ajustados para un diseño experimental desbalanceado o
comparación de rangos múltiples de Promedios y la Prueba de Rangos múltiples de
Duncan. Las mismas técnicas se utilizaron para las 30 familias en los tres sitios. El tamaño
y la tasa de crecimiento de las plantas fue similar en las 5 procedencias y en los tres sitios,
aún cuando la plantación del sitio San Felipe Bacalar se estableció un año después que los
otros. En la mayoría de las variables estudiadas, en cada sitio, no hubo diferencias
significativas entre procedencias y entre familias dentro de procedencias. En el análisis con
la Prueba de Duncan, tampoco se encontró un patrón definido entre las procedencias y en
las 30 familias.
INFLUENCIA DEL FENOMENO CLIMATICO “EL NIÑO” (ENSO) EN LAS
PERTURBACIONES NATURALES A LOS BOSQUES. Verónica Reyero Hdz1 y
Alejandro Velázquez Martínez2
1
Candidata a M.C. Programa Forestal, CP.
2
Investigador Titular, Prog. Ftal., CP.
INTRODUCCION. Los problemas ambientales en México han derivado del subdesarrollo
económico y una deficiente administración gubernamental. Las actividades antropógenas
han conducido al empobrecimimiento del medio y por consiguiente a una depauperización
económica. En general, cualquier actividad humana que disminuya la cantidad de ozono de
la estratósfera puede tener efectos de largo alcance sobre el clima y la existencia de las
especies. La Oscilación del Sur y “El Niño” son parte de un mismo fenómeno con
interacción entre atmósfera y Oceáno Pacífico, su explicación más pausible física y
dinámicamente son las formas de inestabilidad en esta interacción.
ANTECEDENTES. Las oscilaciones son moduladas por las estaciones del año, siendo
mayores en el verano y menores en invierno. A su vez por oscilaciones interanuales sin
tener un periodo regular; su estudio se realiza basándose leyes de la física de la atmósfera y
el oceáno y los modelos de circulación general (GCM). Los cambios anuales que produce
el clima como condiciones extremas (periodos de secas con cosechas pobres, hambrunas y
migraciones masivas) así mismo, la silvicultura se ve afectada.
RESULTADOS. En los últimos 30 años la variabilidad interanual esta relacionada con “El
Niño”(eg. El Huracán Paulina), está se conoce desde el siglo pasado como un periódo de 2
a 4 años al que se le denomina “Oscilación del Sur”. La cantidad de energía calorífica
aumenta en el Pacífico Central ocurriendo un corrimiento de los patrones de lluvia; pude
alterar el clima en regiones distantes como Perú, E.U., Sudáfrica, Brasil con sequías
intensas impactando la actividad silvícola y agrícola, y en Australia e India con la
ganadería. La preocupación de tal fenómeno estriba en una afectación mayor por explosión
demográfica que obliga a asentamientos en zonas de alto riesgo, este fenómeno no tiene
una periodicidad por lo tanto se complica su predicción. Sus impactos tienen grandes
repercuciones, las lluvias se debilitan durante los veranos y la sequía aparece en la Costa
Oeste de México; se presentan sequías , incendios, pérdida de cosechas, e l último evento
(97-98) con daños por 8 millones de pesos, además se presenta el “efecto cascada”, ya que
los procesos de extracción de recursos ocasiona fallas del mercado, lo que tiende a una tala
clandestina de árboles, pérdida de biodiversidad y por lo tanto deterioro ambiental, cuyo
costo no se contempla dentro de los esquemas económicos.
CONCLUSIONES. Los factores determinantes del impacto térmico del “Niño” que
aumenta la temperatura y la precipitación son: variación en la cantidad de energía solar que
llega a la Tierra y su incidencia sobre la superficie, en las propiedades del aire y en la
rotación ésta sobre un plano inclinado. México ha tomado acciones preventivas debido al
aumento de interés por productores silvícolas, aseguradoras, compañías generadoras de
energía y sociedad civil, comenzando a trabajar en esquemas de pronóstico a largo plazo
aplicando el principio de precautoriedad.
ESTRUCTURA ARBÓREA DE UN BOSQUE SECUNDARIO TROPICAL EN EL
SUR DE YUCATÁN Y SU POTENCIAL DE MANEJO. Centeno Erguera, Librado
Roberto y Rivera Leyva, Refugio
Instituto Nacional de Investigaciones Forestales y Agropecuarias. CIR-Sureste. Km. 24
carr. Mérida-Motul, Mocochá, Yucatán. fpvalera@sureste.com
Resumen: Los bosques secundarios surgen por la perturbación de la vegetación tanto por el
hombre como por la naturaleza. En el estado de Yucatán estos bosques representan una
proporción creciente del recurso forestal. Es imprescindible entonces, determinar el
potencial de dichos bosques para la producción forestal y su incorporación al desarrollo
local y/o regional. Se caracterizó la estructura arbórea de un rodal de bosque secundario de
aproximadamente 20 años de edad y derivado de una selva mediana subcaducifolia. La
estructura arbórea de este rodal está determinada por 6 categorías diamétricas (individuos <
7.5 cm de DAP), un área basal de 23 m2, y volúmenes total, comercial y aprovechable de
130, 73 y 8 m3 por hectárea, respectivamente. De un total de 1,679 individuos arbóreos
registrados, más del 65 % se concentra en la categoría de 10 cm y solamente el 0.2 % (3
individuos) en la categoría mayor (35 cm.). Las especies con mayor aportación son:
Lysiloma latisiliquum, Bursera simaruba, Piscidia communis, Diospyros anisandra y
Thouinia pausidentata. Estas cinco especies, que juntas representan el 58 % de individuos
por hectárea, aportan el 74, 76 y 75 % del área basal y volúmenes total y comercial,
respectivamente. El volumen aprovechable está concentrado en L. latisiliquum, en
individuos con DAP mínimo de 25 cm. Se concluye que este rodal de bosque secundario
presenta características adecuadas para un manejo forestal intensivo y ofrece un alto
potencial para la producción maderable.
STIMULATION OF ROOT AND SHOOT GROWTH BY SALICILYC ACID IN
Pinus patula Schl. Et Cham. San Miguel-Chávez R.1, M. Gutierrez-Rodríguez1 and
Larque-Saavedra A.2
1
Colegio de Postgraduados, Carr. México-Texcoco Km 36.5, Montecillo, 56230 México;
Centro de Investigación Científica de Yucatán, Calle 43 No. 130 Col. Chuburná de
Hidalgo, Mérida, Yuc. 97200 México.
2
Abstract: Salicilyc acid (SA) is phenolic compound recently recognized as plant growth
regulator involved in many physiological processes such as thermogenesis in Arum lilies
inflorescence, inhibition of ethylene synthesis, disease resistance, etc. (Raskin, 1995). Some
effects of application of SA have shown diverse responses including seed germination;
reducing transpiration in leaves and epidermal strips, increasing the pod number and yield
in mung beans, etc. (Raskin, 1995). In our laboratory, Gutiérrez-Coronado et al. (1998)
found that SA sprayed on leaves increases significantly the root growth in soybean plants,
and Gutiérrez-Rodríguez et al,. 1999, found that SA stimulated root growth in carrot,
radish, and beet plants. Its important to know if SA stimulated root growth in ligneous
species such as Pinus patula Schl. Et Cham, one specie extensivily planted in parks,
gardens and forests of México (Perry, 1991). The experiment was carried out with
seedlings 3 months-old of P. patula under greenhouse conditions. Salicilyc acid was
sprayed every month on shoots in concentrations from 10-10 M to 10-4 M. After 9 month,
the seedlings were hervested root length, root fresh weight, root dry weigth, shoot height,
shoot diameter, shoot fresh weight, and shoot dry weight were determinad. The results
indicated that SA alters the growth of roots and shoots, and a sgnificant increase in all the
parameters measured were found in seedlings sprayed with 10-10 M to 10-6 M of SA in
comparison with the control treatment. SA increased root length as much as 31% and an
increase of 56% for shoot hieght. Other studies related to root stimulation have found that
SA in combination with indoleacetic acid (IAA) stimulated adventitious root initiation in
mung beans (Ling, 1995).
Gutiérrez-Coronado M.A., Trejo-López C. and A. Larqué-Saavedra. 1998. Effects of
salicylic acid on the growth of roots and shoots in soybean. Plant Physiol. Biochem., 36 (8):
563-565.
Gutiérrez-Rodríguez M., Aristeo C. P., San Miguel Ch. R., A. Larqué-Saavedra 1999.
Stimulation of root growth by salicylic acid in carrot, radish and table beet. In: Abstracts of
XVI International Botanical Congress. St. Louis, USA. P. 652.
Ling, L. 1995. Effects of resorcinol and alicylic acid on the formation of adventitious roots
on hypocotyl cutting of Vigna radiata. Journal of Tropical and Subtropical Botany 3:67-71.
Perry, J. P. 1991. The pine of Mexico and Central America. Timber Press, Inc. USA. 231 p.
Raskin, I. 1995. Salicylic acid. In: Davies J. P. (ed). Plant hormones Kluwer Academic
Publishers. pp: 188-205.
LAS ORQUÍDEAS SILVESTRES EN CAMPECHE. Antonio Sánchez Martínez y
Joann M. Andrews
El estado de Campeche es el estado mexicano con la mayor cantidad de su territorio en
estatus de protegido, con más del 30% lo que significa poco más de un millón de
kilómetros cuadrados. Sin embargo, también es de los estados cuya flora es menos
conocida y estudiada. Las orquídeas silvestres en Campeche son aproximadamente 100
especies, lo cual representa aproximadamente el 10% de las que vegetan en México. Sin
embargo, no existe una lista completa garantizada, por lo que resulta vital tenerla, toda vez
que el recurso natural del estado se encuentra bajo constante presión y sujeto a múltiples
siniestros, naturales o antropocéntricos, como incendios y huracanes. Dichos siniestros
provocan la destrucción de miles de hectáreas arboladas cada año, poniendo en grave riesgo
la diversidad florística del Estado. Por lo anterior se hace necesario tener el conocimiento
de las especies que actualmente habitan en el Estado, para así poder realizar un plan de
manejo y conservación de las mismas; además de establecer programas de rescate para
aquellas especies que se encuentren amenazadas o en peligro de extinción. Los principales
resultados que se tienen después de tres años son los siguientes: se han encontrado 78
especies, incluyendo terrestres, epífitas y semiacuáticas. Además se tienen los reportes de la
existencia de por lo menos otras 20, lo cual nos hace llegar a la conclusión de que ha
aumentado la cantidad de orquídeas que vegetan naturalmente en Campeche. Entre las
especies encontradas, se tienen a nuevos reportes para el estado, tales como Prosthechea
radiata y Cyrtopodium macrocarpum, también se tienen nuevas especies tales como
Lophiaris andrewsiae, Habenaria pringlei y Epidendrum martinezii. Se ha podido observar
que la parte sur y sureste del Estado es la más rica en cantidad de especies, las cuales son
encontradas tanto en la selva mediana subperennifolia como en la selva baja subcaducifolia.
Entre los géneros con mayor cantidad de especies se encuentran Encyclia, Epidendrum y
Habenaria; la especie de más difícil localización es Psygmorchis pusilla y la más
ampliamente distribuida es Catasetum integerrimum; se tienen diversas especies con flores
minúsculas de los géneros Pleurothallis, Stelis y Trichosalpinx. La especie con la
inflorescencia más grande es Rhyncholaelia digbyana, cuyas flores alcanzan hasta 20 cm de
diámetro. En este trabajo se presente un resumen macro del libro *Las orquídeas de
Campeche*, en el cual se presentan a las primeras 57 especies, con su descripción botánica,
mapas de distribución nacional y estatal, dibujos de las plantas y sus partes, así como una
fotografía de la inflorescenia. Se proporciona, asimismo, una introducción donde se abunda
sobre la situación geográfica y ecológica del estado, así como conclusiones finales y la lista
completa de las especies que vegetan en Campeche.
PRESENTACIÓN .................................................................................................................. 1
ANTECEDENTES ................................................................................................................. 2
Problema por abordar ......................................................................................................... 2
OBJETIVOS ........................................................................................................................... 3
TEMÁTICA ........................................................................................................................... 3
RESÚMENES ........................................................................................................................ 4
GLOBAL CLIMATE CHANGE AND ITS IMPACTS ON THE TERRESTRIAL
ECOSYSTEM. Sagar Krupa .......................................................................................... 4
TROPICAL N-FIXING TREES, VIRUS RESISTANCE, AND THE COLLAPSE OF
MAIZE-BASED CIVILIZATIONS. James L. Brewbaker ............................................ 5
EL USO DE ESPECIES ARBÓREAS MEXICANAS PARA PROPÓSITOS
PALEOCLIMÁTICOS. José Villanueva Díaz1, Dave W. Stahle2, Matthew D.
Therrell2, Malcom K. Cleaveland2 y Jorge Sánchez Sesma3.......................................... 6
POTENTIAL CONTRIBUTIONS OF MANAGED FORESTS TO CARBON
SEQUSTRATION: A CASE STUDY EXAMINATION OF SOPUTHERN PINE
FORESTRY. K.H. Johnsen ............................................................................................ 8
GENES, CLIMATE, AND WOOD: A STORY OF LODGEPOLE PINE. Gerald E.
Rehfeldt .......................................................................................................................... 9
CHANGING ATMOSPHERIC CONDITIONS .............................................................. 10
CAMBIOS EN LAS CONDICIONES ATMOSFÉRICAS ............................................. 10
EFFECTS OF FORESTRY PRACTICES, INCLUDING CLEARCUT
HARVESTING AND ALTERNATIVE VEGETATION MANAGEMENT
TREATMENTS ON FOREST MICROCLIMATE. Phillip E. Reynolds .................... 10
WILDFIRES AND GLOBAL CLIMATE CHANGE ALONG A TRANSECT
THROUGH THE AMERICAS. David V. Sandberg1 and Ernesto Alvarado2........... 11
WILDFIRES IN TROPICAL FORESTS. Ernesto Alvarado1 and David V. Sandberg2
...................................................................................................................................... 12
VALIDATING THE INTEGRATED BIOSPHERE SIMULATOR (IBIS) AT
REGIONAL AND LOCAL SCALES IN CANADIAN FOREST ECOSYSTEMS.
Mustapha El Maayar, David Price and Martin Siltanen ............................................... 13
CARBON SEQUESTERING ........................................................................................... 14
CAPTURA DE CARBONO............................................................................................. 14
QUANTIFICATION OF SITE- AND SPECIES-SPECIFIC WOOD PRODUCTION
AND CARBON SEQUESTRATION IN RELATION TO CLIMATE CHANGE LODGEPOLE PINE, INTERIOR SPRUCE AND INTERIOR DOUGLAS-FIR.
Cheng C. Ying1 , Gordon Nigh1 , and Hong Qian2 ...................................................... 14
SOIL CO2 EFFLUX IN RESPONSE TO FERTILIZATION AND MULCHING
TREATMENTS IN A TWO-YEAR-OLD LOBLOLLY PINE PLANTATION IN
THE VIRGINIA PIEDMONT. Robert Pangle and John Seiler. .................................. 15
THE EFFECTS OF PLANTING DENSITY ON CARBON PARTITIONING
BETWEEN FINE ROOTS, LEAF BIOMASS AND STEM GROWTH. Colter Burkes,
Rodney E. Will and Robert O. Teskey ......................................................................... 16
RECALCITRANT SEED & GERMPLASM CONSERVATION ................................... 17
SEMILLA RECALCITRANTE Y CONSERVACIÓN DE GERMOPLASMA ............. 17
GERMINATION OF CO2 ENRICHED Pinus taeda L. SEED AND SUBSEQUENT
SEEDLING GROWTH RESPONSES TO CO2 ENRICHMENT. Mark E. Kubiske1 ,
Manzoor Hussain1, Kristina F. Connor2 ...................................................................... 17
STATUS OF BUR OAK (Quercus macrocarpa) IN NEW BRUNSWICK, CANADA
AND IMPLICATIONS FOR GENE CONSERVATION. D.A. McPhee and J.A. Loo
...................................................................................................................................... 18
BIOLOGICAL RESPONSE TO CHANGE ..................................................................... 19
RESPUESTA BIOLÓGICA AL CAMBIO ..................................................................... 19
EFFECTS OF ELEVATED CO2 AND TEMPERATURE ON THE RESPONSE OF
PONDEROSA PINE TO OZONE: A SIMULATION ANALYSIS. David T. Tingey1,
John Laurence2, James A Weber1, Joseph Greene1, William E. Hogsett1, Sandra
Brown3 and E. Henry Lee1 .......................................................................................... 19
EFFECTS OF WATER STRESS ON WATER POTENTIAL AND STOMATAL
CONDUCTANCE OF FOUR Pinus SPECIES. Eladio H. Cornejo-Oviedo1 and
William Emmingham2 ................................................................................................. 20
DEEP ROOT GROWTH AND WATER RELATIONS IN RESPONSE TO
THROUGHFALL EXCLUSION IN A LOBLOLLY PINE PLANTATION. Mary
Anne Sword1 and Zhenmin Tang2 ................................ Error! Bookmark not defined.
ENVIRONMENTAL INFLUENCES ON GAS EXCHANGE IN FERTILIZED AND
NON-FERTILIZED LOBLOLLY PINE STANDS. Christopher Gough1, John Seiler1,
Kurt Johnsen2................................................................................................................ 22
CARBON DIOXIDE CONCENTRATIONS IN TREE STEMS AND THEIR
EFFECT ON APPARENT STEM RESPIRATION. Robert O. Teskey and Mary Anne
McGuire ........................................................................................................................ 23
LEAF BIOCHEMICAL CHANGES INDUCED IN Populus trichocarpa BY
ENHANCED UV-B RADIATION AND CONCOMITANT EFFECTS ON
HERBIVORY BY Chrysomela scripta (Colepoptera: Chrysomelidae). Jeffrey M.
Warren and John H. Bassman....................................................................................... 24
PHYSIOLOGICAL RESPONSES OF FIELD-GROWN LOBLOLLY PINE TO
SUMMER DROUGHT. Zhenmin Tang1 , Jim L. Chambers1 , Mary Anne Sword2 ,
and James P. Barnett2 ................................................................................................... 25
A COMPARISON OF SOIL TEMPERATURE EFFECTS ON GROWTH AND
PHYSIOLOGY IN WHITE SPRUCE (Picea glauca) AND ASPEN (Populus
tremuloides). Simon M. Landhausser and Victor J. Lieffers....................................... 26
EFFECT OF DIFFERENT DAY-TIME AND NIGHT-TIME TEMPERATURE
REGIMES ON THE FOLIAR RESPIRATION OF Pinus taeda; PREDICTING THE
EFFECT OF VARIABLE TEMPERATURE ON ACCLIMATION. Rodney Will .... 27
ROOT BIOMASS AND SOIL CO2 EFFLUX OF MID-ROTATION LOBLOLLY
PINE EXPOSED TO ELEVATED CO2 AND FERTILIZATION. K.H. Johnsen, L.W.
Kress, J.R. Butnor and C.E. Maier .............................................................................. 28
VEGETATION RESPONSE & CLIMATE CHANGE ................................................... 29
RESPUESTA DE LA VEGETACIÓN Y CAMBIO CLIMÁTICO ................................ 29
NATURALLY REGENERATED LONGLEAF PINE SEEDLING DYNAMICS IN A
CHANGING CLIMATE. Anne Carraway ................................................................... 29
THE INFLUENCE OF ELEVATED TEMPERATURE ON BIOMASS
ALLOCATION AND FOLIAR RESPIRATION IN JACK PINE (Pinus banksiana
Lamb.) AND PITCH PINE (Pinus rigida Mill.) Schedlbauer, J.L. Day, M.E., and
Livingston, W.H. .......................................................................................................... 30
15-YEAR HEIGHT OF Pinus ponderosa IS CORRELATED WITH DIURNAL
TEMPERATURE VARIATION DURING BUD ELONGATION. John N. Church, 1,
Richard S. Criddle, 2 and Lee D. Hansen, 3 ................................................................. 31
POTENTIAL IMPACT OF CLIMATIC CHANGE ON GROWTH AND WOOD
QUALITY IN WHITE SPRUCE. Christophe Andalo1,2, Jean Beaulieu1 & Jean
Bousquet2 ...................................................................................................................... 32
GENETICS AND FOREST TREE IMPROVEMENT .................................................... 33
GENÉTICA Y MEJORAMIENTO DE ÁRBOLES FORESTALES .............................. 33
FOREST MANAGEMENT IMPACTS ON THE GENETIC DIVERSITY OF
EASTERN HEMLOCK. G.J. Hawley1 , D.H. DeHayes1 and J.C. Rrissette2 ............ 33
EVOLUTIONARY RELATIONSHIPS OF SLASH PINE (Pinus elliottii) WITH ITS
TEMPERATE AND TROPICAL RELATIVES. R.C. Schmidtling and V. Hipkins .. 34
HYBRIDIZATION AND GENE FLOW BETWEEN Pinus caribaea AND P.
oocarpa. Robert D. Westfall and Paul Hodgskiss ........................................................ 35
GENETIC VARIATION IN THE PERFORMANCE POTENTIAL OF INTERIOR
SPRUCE SOMATIC SEEDLINGS. Steven C. Grossnickle and Raymund Folk ........ 36
LANDSCAPE GENETIC STRUCTURE OF Pinus banksiana: ALLOZYME
VARIATION. Cuauhtemoc Saenz-Romero1, Raymond P. Guries2, Andrew I. Monk2
...................................................................................................................................... 38
A CASE STUDY OF A PROVENANCE TEST USING TREND ANALYSIS WITH
CORRELATED ERRORS AND SAS PROC MIXED. Cuauhtemoc Saenz-Romero1,
Erik V. Nordheim2, Raymond P. Guries2 and Peter M. Crump3 ................................ 39
FIELD RESULTS OF WHITE PINE BLISTER RUST RESISTANCE IN SUGAR
PINES AND WESTERN WHITE PINE SEEDLINGS. Andrew D. Bower and
Richard A. ..................................................................................................................... 40
LANDSCAPE GENETIC STRUCTURE OF Pinus banksiana: SEEDLING TRAITS.
Cuauhtemoc Saenz-Romero1 and Raymond P. Guries2 .............................................. 41
EL MEJORAMIENTO GENÉTICO FORESTAL Y SU APLICACIÓN EN MÉXICO.
Lilia del C. Mendizábal Hdez, Juan Alba Landa y Armando Aparicio Rentería. ........ 42
POLIMORFISMO BIOQUÍMICO EN SEMILLAS DE GENOTIPOS ELITES DE
Pinus greggii Engelm, EN VERACRUZ, MÉXICO. Lourdes G. Iglesias, Sergio L.
Corro y Armando Aparicio ........................................................................................... 43
FOREST TREE PHYSIOLOGY ...................................................................................... 44
FISIOLOGÍA DE ÁRBOLES FORESTALES ................................................................ 44
INTERSPECIFIC DIFFERENCES IN RATES OF BASE CATION
IMMOBILIZATION IN THE STEM OF SOME HARDWOODS OF EASTERN
CANADA ARE LARGELY AGE- OR SIZE- DEPENDENT. Patricia Boucher and
Benoît Côté ................................................................................................................... 44
USE OF GROUND PENETRATING RADAR TO STUDY TREE ROOTS IN THE
SOUTHEASTERN UNITED STATES. J.R. Butnor1, J.A. Doolittle2, L. Kress1, S.
Cohen1, D. Delea3, and K.H. Johnsen1 ......................................................................... 45
DEPTH OF SENSOR PLACEMENT AND TREE SIZE AFFECT SAP FLUX
DENSITY MEASUREMENTS OF LOBLOLLY PINE. Shufang Yu1, Jim L.
Chambers1, Guddanti Suresh1, Zhenmin Tang1, P. Joy Young1, Mary Anne Sword2,
and James P. Barnett2 ................................................................................................... 46
INFLUENCE OF INTENSIVE MANAGEMENT ON CANOPY TRANSPIRATION
IN LOBLOLLY PINE. Thomas Stokes1, Lisa Samuelson1, Greg Somers1 and Tom
Cooksey2 ....................................................................................................................... 47
EFFECTS OF JIFFY FORESTRY PEAT PELLETS ON ROOTING AND
SUBSEQUENT FIELD PERFORMANCE OF STEM CUTTINGS OF LOBLOLLY
PINE. Anthony V. LeBude, Frank A. Blazich and Barry Goldfarb ............................. 48
RELATIONSHIP BETWEEN HYDRAULIC PATHWAY LENGTH AND FOLIAR
13C IN LONGLEAF PINE. Price C. McLemore, III, Lisa J. Samuelson, Greg L.
Somers .......................................................................................................................... 49
BREEDING FOR STRESS TOLERANCE ..................................................................... 50
CRUZAMIENTOS PARA TOLERANCIA AL ESTRÉS ............................................... 50
GENETIC VARIATION IN DROUGHT HARDINESS OF COASTAL DOUGLASFIR SEEDLINGS. T.S. Anekonda, M.C. Lomas, and W.T. Adams............................ 50
GROWTH EFFICIENCIES OF DIVERSE Pinus taeda FAMILIES AS AFFECTED
BY GENETICS OF THE ROOT SYSTEM. James E. Grissom and Steven E.
McKeand ...................................................................................................................... 51
NORMS OF REACTION OF STABLE AND UNSTABLE DOUGLAS-FIR
GENOTYPES ACROSS TEMPERATURE AND MOISTURE REGIMES:
IMPLICATIONS FOR BREEDING AND CLIMATE CHANGE. Sally N. Aitken and
Tongli Wang ................................................................................................................. 52
TROPICAL SILVICULTURE ......................................................................................... 53
SILVICULTURA TROPICAL......................................................................................... 53
REGENERATION OPTIONS FOR RAPID ESTABLISHMENT OF Pinus greggii
SEEDLINGS. Arnulfo Aldrete1 and John G. Mexal2................................................... 53
ASPECTOS ECOLOGICOS Y DE DENSIDAD DE LA REGENERACION DE Picea
EN NUEVO LEON, MÉXICO. Salvador Valencia-Manzo1, Celestino Flores-López,
...................................................................................................................................... 54
Sergio Braham-Sabag, Miguel A. Capó-Arteaga ......................................................... 54
NURSERY CULTURAL PRACTICES AFFECT EARLY SURVIVAL AND
GROWTH OF TROPICAL HARDWOODS FOLLOWING OUTPLANTING. R.A.
Cuevas Rangel, J.G. Mexal, P. Negreros Castillo and C. Parraguirre Lezama ............ 55
PRODUCCIÓN DE SEMILLAS DEL GÉNERO PINUS EN HUERTOS Y
RODALES SEMILLEROS DE SMURFIT CARTÓN DE COLOMBIA. N. Isaza1 ,
W. S. Dvorak 2 , & J. López Upton 3 ........................................................................... 56
CAUSES AND CONSEQUENCES OF SHOOT BORER (Hypsipyla grandella)
ATTACK IN A MAHOGANY PROVENANCE STUDY IN PUERTO RICO. Sheila
E. Ward and Darlene Waterman .................................................................................. 57
PREDICCIÓN DEL RENDIMIENTO Y TURNOS DE ROTACIÓN PARA
PLANTACIONES DE CAOBA EN QUINTANA ROO, MÉXICO. Xavier García
Cuevas. ......................................................................................................................... 58
ADAPTATION & CLIMATE CHANGE ........................................................................ 60
ADAPTACIÓN Y CAMBIO CLIMÁTICO .................................................................... 60
GENECOLOGY AND ADAPTATION OF DOUGLAS-FIR TO CLIMATE
CHANGE. Brad St. Clair1, Ken Vance-Borland2 and Nancy Mandel1 ....................... 60
ADAPTIVE PHYSIOLOGICAL AND MORPHOLOGICAL RESPONSE OF RED
SPRUCE, BLACK SPRUCE AND THEIR HYBRIDS. J.E. Major, A. Mosseler, D.
Barsi and M. Campbell ................................................................................................. 61
EFFECTS OF CLIMATE ON WEEKLY DIAMETER GROWTH OF 9
BALCYPRESS (Taxodium distichum (L.) Rich) PROVENANCES. P.J. Young and
J.L. Chambers ............................................................................................................... 62
DIVERSITY AMONG F1 PROGENY ALLOWS RAPID SPECIES ADAPTATION
TO CLIMATIC TEMPERATURE CHANGE. R.S. Criddle1, J. N. Church2, M.
Bacca3, Lorraine Wiley4 , and L. D. Hansen5 ............................................................... 63
AIR POLLUTION EFFECTS ON WINTER ADAPTATION IN YELLOW BIRCH.
R. M. Cox1. X-B. Zhu2. and J. W. Malcolm1 ............................................................... 64
POSTERS ......................................................................................................................... 65
CARTELES ...................................................................................................................... 65
COMPARISON AND STANDARDIZATION OF FOUR SOIL CO2 EVOLUTION
MEASUREMENT TECHNIQUES UNDER LABORATORY AND FIELD
CONDITIONS. J.R. Butnor1 ........................................................................................ 65
POTENTIAL RELATIONSHIP BETWEEN 11-YEAR SUNSPOT CYCLE AND
TREE-RING CHRONOLOGY OF TWO HARDWOODS OF EASTERN CANADA.
Benoît Côté and Mohammed Idris............................................................................... 66
SITE PREPARATION TILLAGE IMPROVES LOBLOLLY PINE SEEDLING
(Pinus taeda L.) GROWTH IN THE PIEDMONT AND UPPER COASTAL PLAIN
OF THE SOUTHEASTERN UNITED STATES. M. J. Wheeler, R. E. Will, D.
Markewitz, D. M. Shirley, M. A. Jacobson .................................................................. 67
ESTIMATES OF WATER USE BY NATIVE VEGETATION: AN IMPORTANT
COMPONENT IN EVALUATING THE EFFECTIVENESS OF
PHYTOREMEDIATION. James M. Vose and Katherine J. Elliott ............................ 68
INFLUENCE OF INTENSIVE MANAGEMENT ON NET ECOSYSTEM .............. 69
PRODUCTIVITY OF LOBLOLLY PINE (Pinus taeda). Michelle Ducharme1, Mandy
1
Tran , Lisa Samuelson1, Kurt Johnsen2, Tom Cooksey3 .............................................. 69
HIGH LEVELS OF GENETIC DIFFERENTIATION AMONG POPULATIONS OF
MEXICAN CONIFERS. F. Thomas Ledig1, Jesús Vargas Hernández2, and Basilio
Bermejo Velázquez3 ..................................................................................................... 70
WATER AND CARBON RELATIONS OF Pinus elliottii FLATWOODS
SUBJECTED TO SEVERE DROUGHT. Timothy A. Martin .................................... 71
GENE CONSERVATION OF PACIFIC NORTHWEST CONIFERS: IN SITU AND
EX SITU ANALYSES. Sara Lipow1, Brad St. Clair2 and Ken Vance-Borland1 ........ 72
MICROELECTRODE TECHNOLOGY FOR MEASURING XYLEM SAP CO2
CONCENTRATIONS. Mary Anne McGuire and Robert O. Teskey ......................... 73
REGULATION OF ECOSYSEM FUNCTIONS ACROSS COMPLEX
ENVIRONMENTAL GRADIENTS IN LONGLEAF PINE (Pinus palustris)WIREGRASS (Aristida stricta) WOODLANDS. Robert J. Mitchell1, L. Katherine
Kirkman1, Stephen D. Pecot1, Carlos A. Wilson1, Lindsay R. Boring1, Joseph J.
Hendricks2, Ron Hendrick3, and James A. Vose4......................................................... 74
OVERSTORY STRUCTURE AND REGENERATION PROCESSES IN
LONGLEAF PINE-WIREGRASS FORESTS. Robert J. Mitchell1, Brian J. Palik2,
Robert H. Jones3, Mou Pu4, Stacy Hurst1, Stephen D. Pecot1, Michael A. Battaglia4,
and Glen L. Stevens3 .................................................................................................... 75
CARBON – FINE ROOT ALLOCATION AND TRANSFER AT ECOSYSTEM
SCALES (C-FATES). Durwin C. Carter1, Joseph J. Hendricks1, and Robert J.
Mitchell2 ....................................................................................................................... 76
ENVIRONMENTAL CONTROLS ON LEAF AND CONOPY CONDUCTANCE OF
LONGLEAF PINE (Pinus palustris Mill.). Robert N. Addington1, Robert J. Mitchell2,
and Lisa A. Donovan1 ................................................................................................... 77
ASSESSING THE PATTERNS AND CONTROLS OF FOLIAR LITTER
DECOMPOSITION LONGLEAF PINE-WIREGRASS ECOSYSTEMS. Lindsay R.
Boring1, Joseph J. Hendricks2, Carlos A. Wilson1, and Mary L. Cobb1 ...................... 78
NITROGEN DYNAMICS IN A LONGLEAF PINE-WIREGRASS WOODLAND.
Carlos A. Wilson1, Robert J. Mitchell1, Joseph J. Hendricks2, and Lindsay R. Boring1
...................................................................................................................................... 79
TREE RADIAL GROWTH AND UNDERSTORY VEGETATIVE PRODUCTION
IN A 30-YEAR-OLD THINNED BOTTOMLAND OAK PLANTATION. K.L.
Wharton1, J.L. Chambers1, J.S. Meadows2 and K.F. Ribbeck3 ................................... 80
ROOTS CAN DRIVE GROWTH OF TREE SEEDLINGS. James E. Grissom and
Steven E. McKeand ...................................................................................................... 81
FINE ROOT GROWTH IN LOBLOLLY PINE SUBJECTED TO FERTILIZATION
AND CO2 TREATMENTS. Kim H. Ludovici and Lance W. Kress. ........................... 82
HERBACEOUS FLORA AS INDICATORS OF SUGAR MAPLE SITE QUALITY.
Stephen B. Horsley 1, Robert P. Long 2 and Scott W. Bailey 3 ................................... 83
THE EFFECT OF FERTILIZATION ON GAS EXCHANGE AND GROWTH OF
MATURE LONGLEAF PINE. Anderson, P.H., and K.H. Johnsen ............................ 84
MANAGEMENT IMPLICATIONS OF WHITE PINE BLISTER RUST INFECTION
AND MORTALITY THROUGH AGE 15 IN SUGAR PINE IN SOUTHWESTERN
OREGON. Richard A. Sniezko1, Andrew D. Bower1 and Ellen M. Goheen2 ........... 85
GENETIC DIVERSITY AND RESTORATION OF A DISJUNCT PITCH PINE
POPULATION IN VERMONT, U.S.A. G.J. Hawley1, D.H. DeHayes1 and P.G.
Schaberg2 ...................................................................................................................... 86
CALCIUM DEPLETION: A THREAT TO FOREST HEALTH AND
SUSTAINABILITY? G.J. Hawley1, D.H. DeHayes1 and P.G. Schaberg2 ................ 87
UN ÍNDICE DE HUMEDAD Y TEMPERATURA DEL SUELO
CORRELACIONADO CON LA SOBREVIVENCIA DE PLÁNTULAS. Miguel
Angel Capó Arteaga ..................................................................................................... 88
ESTADO ACTUAL DEL BOSQUE DE Pinus maximartinezii, UN PIÑONERO EN
PELIGRO DE EXTINCIÓN. Miguel Angel Capó Arteaga1 y Edmundo Lara
Rodríguez ..................................................................................................................... 89
EVALUACIÓN TEMPRANA DE PROCEDENCIAS-PROGENIES EN CAOBA
(Swietenia macrophylla King). Bartolo Rodríguez Santiago1, Kevyn Wightman2,
Sheila Ward3 y Jeremy Haggar2 ................................................................................... 90
INFLUENCIA DEL FENOMENO CLIMATICO “EL NIÑO” (ENSO) EN LAS
PERTURBACIONES NATURALES A LOS BOSQUES. Verónica Reyero Hdz1 y
Alejandro Velázquez Martínez2.................................................................................... 91
ESTRUCTURA ARBÓREA DE UN BOSQUE SECUNDARIO TROPICAL EN EL
SUR DE YUCATÁN Y SU POTENCIAL DE MANEJO. Centeno Erguera, Librado
Roberto y Rivera Leyva, Refugio ................................................................................. 92
STIMULATION OF ROOT AND SHOOT GROWTH BY SALICILYC ACID IN
Pinus patula Schl. Et Cham. San Miguel-Chávez R.1, M. Gutierrez-Rodríguez1 and
Larque-Saavedra A.2 ..................................................................................................... 93
LAS ORQUÍDEAS SILVESTRES EN CAMPECHE. Antonio Sánchez Martínez y
Joann M. Andrews ........................................................................................................ 94